The Search For Confidence And The Hot Foot Theory

For an upcoming IntoPress piece on the ‘confidence’ trope in football, I decided to have a speculative foray into the numbers, drawing inspiration from the ever controversial ‘hot hand’ debate in basketball. That piece, one for a more general audience and with a wider discussion of the topic, will be available to read in a magazine edition released in May. The polarized debate to which I wade into can be caricatured as something like this – in mainstream analysis, ‘confidence’ is often the explanation for what others may often call variance. If Harry Kane is on a poor run of goal-scoring form, missing a shot is a consequence of a lack of confidence, and vice versa. To the other camp, the one I confess to intuitively belonging in, this is largely unproven nonsense. In the end, what I found wasn’t quite what I expected. Method The data used was event level data for the Premier League, La Liga, Bundesliga, Serie A, Eredivisie, Championship, and Ligue 1, as far back as the 2012/2013 season. I grouped the shots by player and season, before adding two extra rolling variables to each of them – ‘confidence5’ and ‘confidence10’, where:

ConfidenceX = Number of last X shots to have been a goal

This is by no means a perfect proxy for ‘confidence’ – it barely scrapes the surface of the linguistic connotations of the word, but it’s a starting point. It rolls between games, and so is slightly less vulnerable to score effects and game states, but not seasons. A shot taken by a player who had taken less than 5 or 10 shots in that season would get a Confidence5/10 score of ‘0’. I also randomly ordered the same set of shots and created the same variables in order to have a control group. Aggregating by ‘confidence’ score and looking at average conversion rates, I was then able to test for any discernible linear relationship between the two. Applying Pearson’s Product-Moment Correlation and t-tests at a significance level of (< 0.05), ‘confidence5’ strongly correlated with conversion and in a statistically significant manner, while ‘confidence10’ correlated weakly but without significance. Immediately sceptical of the ‘confidence5’ correlation, I ran the same calculations on the control group; at the rolling 5-shot level, it correlated fairly strongly, but without any statistical significance (p-value ~ 0.2). Nonetheless, I was concerned about sample size issues - in the whole dataset of shots, there were only 16 streaks of 5 goals from the 5 preceding shots, and some of these are the same player in quick succession: in two matches against Hertha Berlin and Werder Bremen last season, Bas Dost managed to take a shot having scored his last five 3 times. In light of this, I filtered out any chances under 0.2 expected goals by my model and ran the same correlation tests – now, for a streak of 5, there were 150 examples (which still isn’t great). At the rolling 5 shot level, the correlation became even stronger and more significant (p-value ~ 0.02). With ‘confidence10’, the relationship was still not significant enough (p-value ~ 0.26) to reject the null hypothesis that it has no bearing on conversion. In terms of the possible effect being observed, this strengthens the possibility of a short-run ‘hot/cold feet’ phenomenon – if this was just picking up player quality, where players who score more will score more, it would probably be significant at the rolling 10-shot level too. Applying the same filter and method to the control group, neither the 5 or 10 level was significantly correlated with conversion. As another check, I looked at the relationship between a shot in the sample’s xG and the average xG of the 5 shots before it – if this was high, any ‘hot feet’ effect could just be a proxy for the repeatability of chance quality at this micro level. As it turned out, they were correlated positively and significantly, but probably too weakly (correlation coefficient of ~ 0.014 by Pearson’s) for this to be the case. Perhaps there really was an effect here. Conf11   The relationship seems to apply to xG conversion too. Conf13 Again, this isn't the case for the control group. Conf12 Going back down to the event level data with a logit regression for all chances over 0.2 xG, again the number of the last 5 chances scored was a significant factor in affecting the probability of one of these chances going in. Predicting the probability of success with this model based on ‘confidence5’ alone, I can then plot the relationship with 95% confidence intervals. The model has a McFadden pseudo-r2 of ~ 0.0022 (these tend to be “considerably lower” than OLS r2s in McFadden’s own words), and so is expectedly a small effect. Conf9

Confidence Predicted Probability of Scoring
0 0. 3521575
1 0. 3745545
2 0. 3975019
3 0. 4209090
4 0. 4446772
5 0. 4687013

According to this, a chance (over 0.2 xG) preceded by 2 goals in the last 5 chances would have roughly a 4% higher chance of going in than one preceded by none. This is loosely equivalent to the difference between taking a shot from 15 metres out and 10 metres out, all else equal. If all 5 had been scored previously, it would predict roughly an 11% higher chance. I would be surprised if the effect was this large and this linear - as can be seen from the larger confidence intervals towards the higher confidence levels, uncertainty is an issue with the decreased sample size of larger streaks. Conclusion Although a small factor, one fairly tiny in terms of affecting the probability of scoring compared to, say, location, a ‘hot feet’ style effect may very well exist in the short run for non-terrible chances. The logical next step is to look at rolling expected goal over-performance as a predictor of shot success - I had a quick look at this and it got very complicated very quickly.   My methods are likely to be imperfect as a second year undergraduate, and like all endeavours in football stats, this is probably going to be complicated by systemic biases. As ever, I’m still sceptical, and so defer to the more capable and qualified to shoot this down. If you have any ideas about a way to improve the methodology or completely up-end it and test the theory in another way, I’m more than happy to talk about it: @BobbyGardiner.  

Leicester City: Need for Speed?

Leicester City's rise to the top of the Premier League has led to many an analysis by now. Reasons for their ascent have mainly focused on smart recruitment and their counter-attacking style of play, as well as a healthy dose of luck. While their underlying defensive numbers leave something to be desired, their attack is genuinely good. The pace and directness of their attack has regularly been identified as a key facet of their style by writers with analytical leanings.

Analysis by Daniel Altman has been cited in both the Economist and the Guardian, with the crux being that the 'key' to stopping Leicester is to 'slow them down'. Using slightly different metrics, David Sumpter illustrated this further at the recent Opta Pro Forum and on the Sky Sports website, where his analysis surmised that:

"For Leicester, it's about the speed of the attack."

An obvious and somewhat unaddressed question here is whether the pace of Leicester's attack is the key to their increased effectiveness this season? Equating style with success in football is often a fraught exercise; the often tedious and pale imitations of Guardiola's possession-orientated approach being a recent example across football.

Below are a raft of numbers comparing various facets of Leicester's style and effectiveness this season with last season.

Comparison between Leicester City's speed of attack and shot profile from 'fast' possessions. A possession is a passage of play where a team maintains unbroken control of the ball. Possessions moving at greater than 5 m/s on average are classed as 'fast'. All values are for open-play possessions only. Data via Opta.

The take home message here is that the average pace of Leicester's play has barely shifted this season compared to last. Only Burnley in 2014/15 and Aston Villa in 2013/14 have attacked at a greater pace than Leicester this season over the past four years.

The proportion of their shots generated via fast paced possessions has risen this year (from 27.5% to 32.1%) and Leicester currently occupy the top position by this metric over this period. In terms of counter-attacking situations, their numbers have barely changed this season (20.1%) compared to last season (20.8%), with only the aforementioned Aston Villa having a greater proportion (21.3%) than them in my dataset.

What has altered is the effectiveness of their attacks this season, as we can see that their expected goal figures have risen. Below are charts comparing their shots from counter-attacking situations, where we can see more shots in the central zone of the penalty area this season and several better quality chances.

Comparison of Leicester City's shots from 'fast' and 'deep' attacks in 2014/15 and 2015/16. Points are coloured by their expected goal value (red = higher xG, lighter = lower xG). Any resemblance to the MK Shot Maps is entirely intentional. Data via Opta.

Their improvement this year sees them currently rank first and second in expected goals per game from fast-attacks and counter-attacks respectively over the past four seasons (THAT Liverpool team rank second and first). Based on my figures, Leicester's goals from these situations are closely in line with expectations also (N.B. my expected goal model doesn't explicitly account for counter-attacking moves).

The figure below shows how this has evolved over the past two seasons, where we see fast-attacks helping drive their improved attack at the end of 2014/15, which continued into this season. There has been a gradual decline since an early-season peak, although their expected goals from fast-attacks has reduced more than their overall attacking output in open-play, indicating some compensation from other forms of attack.

Rolling ten-match samples of Leicester City's expected goals for in 2014/15 and 2015/16. All data is for open-play shots only. Data via Opta.

The effectiveness of these attacks has gone a long way to improving Leicester's offensive numbers. According to my expected goal figures in open-play, they've improved from 0.70 per game to 0.94 per game this season. About half of that improvement has come from 'fast' paced possessions, with many of these possessions starting from deep areas in their own half.

Examining the way these chances are being created highlights that Leicester are completing more through-balls during their build-up play this season. The absolute numbers are small, with an increase from 11 to 17 through-balls during 'fast' possessions and from 6 to 12 during 'fast' possessions from their own half, but they do help to explain the increased effectiveness of their play. Approximately 27% of their shots from counter-attacks include a through-ball during their build-up this season, compared to just 11% last season. Through-balls are an effective means of opening up space and increasing the likelihood of scoring during these fast-paced moves. Leicester's counter-attacks are also far less reliant on crosses this season, with just 2 of these attacks featuring a cross during build-up compared to 9 last season, which will further increase the likelihood of scoring.

Speed is an illusion. Leicester's doubly so.

Overall, attacking at pace is a difficult skill to master but the rewards can be high. The pace and verve of Leicester's attack has been eye-catching but it is the execution of these attacks, rather than the actual speed of them that has been the most important factor. Slowing Leicester down isn't the key to stopping them, rather the focus should be either on denying them those potential counter-attacking situations or diluting their impact should you find yourself on the receiving end of one.

Whether they can sustain their attacking output from these situations is a difficult question to answer. If we examine how well output is maintained from one year to the next, the correlation for expected goals from counter-attacks is reasonable (0.55), while goal expectation per shot is lower (0.30). Many factors will determine the values here, not least the relatively small number of shots per season of this type, as well as a host of other intrinsic football factors. For fast-attacks, the correlations rise to 0.59 for expected goals and 0.52 for expected goals per shot. For comparison, the values for all open-play shots in my data-set are 0.91 and 0.63.

Examining the data in a little more depth suggests that the better counter-attacking and/or fast-paced teams tend to maintain their output, particularly if they retain managerial and squad continuity. Leicester have a good attack overall that is excellent at exploiting space with fast-attacking moves.

Retaining and perhaps even supplementing their attacking core over the summer would likely go a long way to maintaining a style of play that has brought them rich rewards.

Into the Stats: What's Going On In The Premier League?

The first week of April might seem a strange time for a football team to go on holiday, but it seems we already find those stranded in mid-table doing just that; or at least some of them. Bournemouth continued their terrible record against this season's top four, they've managed two draws against Leicester but lost all their other six fixtures, scored three and conceded 22 and Watford, seemingly coasting home, have fared even worse having lost 7/7, while scoring three and conceding 16. All this poses the question: how good are these teams? Bournemouth, despite offering nearly nothing against the top four, have been a superior team outside of these games. I'm not going to suggest that it's been strategic to maximise their play in more competitive games, but it sure would make sense to expend more energy at 1-1 against West Brom or Crystal Palace than go hell for leather when 4-1 down to Tottenham. In more balanced fixtures, they have been defensively strong while putting forward a league average attack. That's good stuff for a newly promoted team and explains why despite some genuine awfulness in those higher profile fixtures, they are sitting comfortably in 13th with the comfort of no more top four fixtures to come. For the whole season, Watford's defence is around league average and their attack is slightly below par, but since the half way point, their attack has been pretty woeful; they are scoring an average of half a goal a game. Why? They are taking under ten shots a game and getting under three of them on target. Who? Odion Ighalo has one league goal in 2016. Not to call Watford a one man team but, well, in attack, they largely  have been. We've seen this before, a player lands in the league, gets hot quickly, scores a ton, attracts transfer talk and sometimes achieves one, then fades. All the more reason to work out if a player has been on a streak or is prone to streakiness before you part with the cash and why goals are merely the icing on a cake: ingredients are all important. For some reason a variety of Newcastle United associated players (Andy Carroll, Demba Ba, Papiss Demba Cissé) are coming to mind here. Again though, criticism of a newly promoted team should be tempered against the fact that they aren't getting relegated; this is literally page one in the "What to do when you reach the Premier League" playbook. And it's entirely possible that the hat-trick could be secured after Norwich City overcame Newcastle in a huge game this weekend. That the three teams under greatest threat of demotion, Sunderland, Newcastle and Aston Villa have all suffered from varying degrees of hapless leadership over multiple years, both on and off the pitch, is probably the most positive indicator to have come out of this strange and turbulent season. I filled one of the many empty seats at Villa Park this weekend (and wrote about it), and the deficiency in the standard of the team put out was clear to see as Chelsea's reserves brushed them aside with next to no fuss. They had miniature midfielders, a back four full of yesterday's men and one tactic that seemed only half conceived–fire it up to the big man, but don't follow up. Of course the league's bottom team is likely to be bad, but that degradation of quality has taken place over a number of years and this relegation could well have occurred before. That it has not, and that Sunderland have survived so long in similar circumstances, has lead to wrongs left without being righted and with the Championship beckoning Villa particularly could be vulnerable to a long stretch. Back to the point about teams being on holiday, we find West Brom having reached the Pulis Line: 40 points. Oh West Brom are on holiday? No chance, this was possibly the most Tony Pulis performance of the whole season. Three shots in total, none of which were on target meant the seventh on target blank of the season, five of which have been away from home and the fifth in the last ten games. Enough for a point though? Sure, because repelling twenty two Sunderland shots is easy– if you are managed by Tony Pulis. Begrudgingly accepting the inevitable With their fifth 1-0 victory in six games, the reality of a Leicester title is genuinely upon us.  I have noted all season the various benefits of skew that the team has enjoyed but at no point did I truly expect them to hold out initially for the top four and once that became impossible to deny, the title. While their likely achievement should be applauded as possibly the biggest odds ever defied in a sporting event (5000/1), that those odds were so long accurately describes the unlikelihood of this coming to pass. The twin powers of Jamie Vardy and Riyad Mahrez powered the first half of this season and only latterly has the team's focus on defence and the skills of N'Golo Kanté and the defense garnished praise. Will Gurpinar-Morgan is writing on Leicester for StatsBomb this week, so I won't labour a point but in a points estimation I created I have them about plus 17 points compared to where you might expect given their shot profile. That's huge and they have excelled and overachieved where all others have failed to do the same. The perfect storm. In particular, the weird incongruent nature between Arsenal's reality and the expectation formulated by their focus on shot location has created a scenario in which despite underachieving, they will probably end up in a similar position to usual. Maybe a bounce up to second place will actually reflect a step forward and technically successful transition towards their tactic of more selective shooting, but even with the benefit of skew, to have failed to mount a sustained challenge at the very top goes down as a disappointment. Similarly for Manchester City, stymied largely by combinations of luck and injury, they will probably look back in May and wonder how they failed to build on their exceptional start and contend. Less is wrong with these two giant clubs than the simple narrative will lead many to believe. Mass clear-outs will not be necessary and both teams will probably be able to regroup and compete next year with just a couple of core signings, probably fewer at Arsenal, as is Arsene's way. Tottenham should reflect on a season of great steps forward and to mourn the title that never was would miss the point. Young, dynamic and full of shooting boots, they should be able to maintain this level of performance going forward and challenge towards the top end once more. It doesn't look like their starlets are going to get picked off but that's the one note of caution worth adding. If Daniel Levy is smart, and evidence suggests he probably is, then he'll put his moody hat on this summer and concentrate on enticing to a top class central midfielder, a forward option and leave his phone on silent. Non Usual Scoring Charts Couple of charts to take a look at player stats. Important to remember that these are all, in the scheme of things, short term skews in fields that do not necessarily indicate future outputs. However, particular extremes may be considered more likely to revert to individual means than not. First the "traditional" shot conversions, with penalties stripped out: conversion 15-16 Hmm... three West Ham players in the top ten? That's interesting. Moving along by way of contrast, from an early iteration of an in-house model, we have the expected goal over/under achievers per shot: xgshot 15-16Well, how about that, it's those three West Ham guys again! We're looking at similar things, so that's not the greatest surprise but there are notable other entrants in these lists. Shinji Okazaki's all shot conversion of 14% is superficially decent, but when matched up against his expected goals, he's undershooting by a fair margin. Being the point on the front of Leicester's attack and most notably having Jamie Vardy and Riyad Mahrez serving up your chances means you should be scoring more than five goals. Ramsey and Walcott's presence on the naughty list is no surprise to those of us up to speed with Arsenal but it's interesting to find two players who may well attract the attention of suitors in the summer on there too. Aleksandar Mitrović and Sadio Mané both look ripe for a transfer, Mitrović having shown more than enough promise to feel that a Championship demotion would be too much at this stage of his career (wait, another Newcastle striker!) and Mané having possibly stayed a year more than anticipated at Southampton. Each has clear room to improve on this year's numbers, as Mitrović notably showed at the weekend and Mané, frustratingly, did not. The goals may have been less plentiful than desired but the quality remains. Roberto Firmino is a tricky one to get a handle on. His first big season was in 2013-14 where he scored 14 non-penalty goals for Hoffenheim and overshot his expected goals numbers significantly. This was quickly countered with the opposite in 2014-15 and now after taking a little while to settle down and struggling to nail a definite position he's back to overshooting expectation once more.  He looked to be a solid acquisition in the summer with clear potential to grow into a top player and i'd still err on the side of positivity going forward. As with many things Liverpool, Firmino looks to be on the cusp of something good, a theory advanced eloquently by Dustin Ward here on StatsBomb mere days ago. So the title is won, relegation is decided, the top four looks locked down. Not much left to say really? Ha, forget it. Plenty more to come, i'll bet. ___________________________________________________ Thanks for reading! Tons has gone on here recently: Site owner Ted Knutson returned from the wilderness of real football with a suite of work:

and a must-read mailbag:

Dustin Ward hit the high notes with a Liverpool breakdown:

And I guested on the Anfield Index: Analytics podcast:

We also have plenty more to come this week so keep alert and don't miss out.

Klopp's Liverpool: Poised to Make the Leap

What were they waiting for? Jurgen Klopp was available during the summer and Liverpool gave Brendan Rodgers another shot. Rodgers seems like a solid enough manager but you pounce when you can get Klopp. Liverpool didn't make the same mistake twice and picked up Klopp after 8 games and turned it around to cruise into the Champions League, setting up years of glory...right? Well, maybe it hasn't been smooth so far but even if the first part hasn't gone according to plan, the second and more long-term view is very rosy for the Reds and Klopp is a big reason for it. Let's take a birds-eye view of where Liverpool are now and where they are going.     A little context Liverpool are a very good shots team this year, but that's not really new. They've been 2nd in TSR in three of the past five seasons with only 1 top-4 finish in the Real Table*. This year's TSR of .626 is 7th best in all of Europe. The only teams with a better rate are Napoli, Juventus, Dortmund, Bayern, Real Madrid, and Man City. That is special company. Their company when it comes to PDO (basically goal% on both ends) is rather less distinguished. Only Bournemouth, Villa, Udinese, Levante, and Espanyol are worse at turning shots into goals and keeping shots from turning into goals.   Snip20160228_29 Here's a quick report card on the rest of the big stuff. Snip20160228_30 We very quickly see that Liverpool are performing right where they want to be on the big picture, most-repeatable stuff: holding the ball, pushing the ball into dangerous areas, keeping opponents from getting the ball into dangerous areas, accumulating shots, and preventing shots. In the Klopp-era all of these things shoot up even higher, to basically 2nd best everywhere. Unsurprisingly to those who have followed Liverpool closely, it's at the final step of the process that the Liverpool machine breaks down. It's business class from NYC to Dallas, and then Greyhound bus to El Paso. And yes, your seat-mate is smoking, does it bother you? The poor shot quality for and against helps explain their horrendous conversion rates and the 9th place standing.     So what are Liverpool? Does the PDO represent a team who has no shot discipline and glaring weaknesses in defense or does that shot rate indicate this team is very close to becoming one a juggernaut? Let's find out.       Field Control   Snip20160331_28 Liverpool last year and at the start of this year were basically a Europa-level team when it comes to tilting the field in their favor. They were good at spending more time in front of the opposition goal than their own but not great, that's changed under Klopp. Now no EPL team dominates territory like Liverpool. Chelsea, Man City, and Arsenal are still really good, but the Reds have done it more than anyone else. When you look through past seasons in different leagues, you essentially never find a team who is the best at dominating territory and fails to at least contend for the title.   Without the Ball Now dominating the field is generally a great thing, but it's not an unalloyed good. Maybe Liverpool are inflating those numbers by pushing too many players forward slowly and becoming extremely exposed on the counter. So while they face the fewest danger zone entires of any team, these might be exponentially more dangerous. And this conclusion is sort of true according to Caley's numbers (high-pressing teams unsurprisingly are up top) but the "very direct" category is not abnormal at all so they aren't being torn apart. If they were being repeatedly shredded and caught upfield you'd expect the defense to break down in front of goal. We don't see this at all. We see the opposite. No team has held opponents to a lower danger zone completion percentage than the Reds: 33.3%.  So under Klopp Liverpool have managed to have a team that can press high effectively, keep teams from reaching the danger zone at an elite level and be the toughest to actually complete a pass in the danger zone against. Only Tottenham have anything like that all over the field and they can't match up when it comes to keeping opponents away from the danger zone.     Snip20160325_7   Snip20160330_14 There are really no weak spots. Only Spurs press high more effectively, no team faces fewer dangerous passes, and no team is harder to complete passes against. So why are they allowing so many goals (only 8th-fewest) with this incredible whole-field shutdown defense?   Snip20160327_12 Liverpool SOT allowed from November-January using Paul Riley's handy viz.   We can see in Klopp's first three full months, Liverpool allowed 18 goals and made 21 saves. Liverpool allow the both highest the goal% and the highest share of shots on target to turn into goals in the Klopp-era. If Liverpool and Leicester switched goal allowed rates, Liverpool would have allowed 10 goals in the Klopp era (instead of 30) and Leicester would have allowed 48 (instead of 16). This low save% is not because of some fundamental flaw in the Liverpool defense. They allow slightly higher quality shots than average but that's inflated by a few brutal mistakes. Snip20160401_36 If you look league-wide at only shots that are sub-.6 xG, Liverpool suddenly allow tougher shots than the average team. Basically there are 6 really high quality shots that make a big difference in the xG/SA rank, I'm willing to guess most came from ridiculous mistakes on a set piece or Kolo's arthritis flaring at an inconvenient time (I still love you Kolo). These are not problems that should persist into next season. If Liverpool are simply average at avoiding boneheaded mistakes next year and replace Simon Mignolet (below average shot-stopper according to Paul Riley's ratings and poor cross-handler) this problem will be solved. A league-average goal% is what you should expect next season.   Going Forward We know they can shoot. 3rd overall but in the Klopp-era we see even stronger numbers: 2nd shots, 2nd shots on target, 2nd in TSR, and 2nd in SOTR. Are they just chucking once they get close and not working the ball around? Absolutely not, no team plays more passes into dangerous areas than Liverpool under Klopp. Can they create any space to complete passes? Sort of. Snip20160327_14 This chart can explain a lot: Liverpool have the most volume but can't quite execute like the 2 powerhouse attacks of City/Arsenal as they are forced into slightly longer passes they can't complete at as high of a rate.   So we shouldn't be surprised if they are a bit behind City/Arsenal when it comes to racking up the goals, but what's with the low shot quality? They haven't gotten many big chances: Snip20160401_38 These two charts have a lot of luck in them, I am far from convinced Norwich and Sunderland have some sort of secret when it comes to creating great chances or that Swansea and West Ham have figured out how to stop them. We can conclude they haven't quite gotten their share of elite chances while have given opponents more than their share. But given that Liverpool are still hovering in the middle even if they had their fair share of opponent mistakes and loose balls turned into tap-ins, how can they improve their chance quality?   Parts 1, 2, and 3 are health from Daniel Sturridge and Coutinho, who have only started 24 of a possible 58 games and when both have finally been healthy in recent games the chances have been more abundant. Those are two of the best attacking players in Europe, and if they play together for a full season there is zero reason Liverpool won't be much higher up this chart next season. To talk about the rest of the cast, we will go to a player rundown.   Player Rundown   -We've already talked about Sturridge and Coutinho where the question is basically just health. Klopp has toned back Coutinho's wild shooting a bit, and playing with Sturridge will do that even more. After months of Benteke, suddenly Coutinho has options in front of him and a striker who can join in the play. Snip20160331_30 -Benteke almost certainly has no future as a big-minute player. He just can't pass the ball and isn't a special shot generator or space-creator. No player on Liverpool has a completion rate below 74% besides Benteke down at 66%. -Roberto Firmino has swung wildly between being underrated and overrated several times this season. He is a great presser of the ball, routinely leading the pack in the fantastic AI Under Pressure charts so he has always provided value even when struggling early. He's scored 8 and assisted 7 with strong key pass numbers but that has likely led to overheated expectations, he's still wasteful with the ball at times (only Benteke has a lower passer rating for Liverpool, a measure of how well his completion% compares to expected comp%), not a shot monster and seems to not really have a clear positional home. There is monster potential here but still some development needed to be a really good attacking player. Snip20160401_40 Defenders generally come out better than attacking players on these rough ratings, so Toure's number is almost unimaginably bad while Coutinho's is what you'd see from one of the best players in the league. -James Milner was never a good fit at midfielder, but has been boringly solid rather well out wide whipping in enormous amounts of crosses (6 per 90). -Jordan Ibe is a fascinating case, no player with >500 minutes has successfully dribbled as much as he has, he gets the ball way down the pitch to where he delivers passes from where Origi/Benteke usually do, he has great passing numbers as far as dangerous completions and a high passer rating yet he remains very frustrating to watch. The enormous dribbling numbers are a part of that, he doesn't seem to play quick passes and holds the ball too long, but the potential remains sky high here. He's only 20 and has a lot of strengths that 25 year olds would kill to have. -The midfield remains a bit hazy. Emre Can is kind of the Firmino of the midfield in that there is a ton of visible potential but he's just not consistent yet. His passing is just not the high quality you want from your primary ball-handler though he is dangerous when he gets forward. He still edges out Henderson, who I think we can simply say at this point is not a great passer. Joe Allen is, my passing metrics really like him and Will's plus/minus adores him. I'd love to see him get a long run but suspect his physical liabilities make him a bit of an unnatural fit for a Klopp side. -The Clyne/Moreno debate is one of those topics that reveals a lot about you as a person.  If you like Moreno more, my theory is you take the risk and order the salmon at the restaurant while Clyne-stans stick with the solid burger. 60% of the time I like taking the risk and going proactive for a fresh, healthy meal with a side of loads of chances in front of goalSnip20160328_2 40% of the time I like the good old solid burger that assures me I won't be leaking out left side later.   Snip20160331_32   Snip20160401_34 Those are some seriously unbalanced fullbacks. Why can't we combine the two?   Sakho remains one of the best center backs at advancing the ball in the league. I love Kolo Toure but his body is failing him and at this point he's probably not even a top-end Championship player. Offseason shopping list: 1. keeper, 2. athletic midfielder, Lucas doesn't have the legs to stay there much longer. Conclusion Liverpool are in as good a long-term situation as they've been in recent history. They dominate the ball and tilt the field in a way that only Man City and Arsenal can match. This years weaknesses have come down to shot quality which has been heavily influenced by shocking and unlucky proportions of top-tier chances allowed and taken. These will likely even out a good bit without anything changing but the underlying causes there are those that have the easiest fixes: a new goalie, a new centerback and a healthy Sturridge and Coutinho. Without the ball, only Tottenham can claim to play nearly as well as the Klopp's squad. If Daniel Sturridge can remain healthy, there is no more complete team heading into next season than Liverpool. Man City and Arsenal's attacking firepower will make them slight favorites but Liverpool should expect to be the 3rd best team within touching distance of the top starting today and going into next season. Liverpool have the coach and the fundamentals and are right at the edge, the next step isn't a hard one to make.

StatsBomb Mailbag - Who Should Arsenal Buy in Midfield + More Transfer Shopping

A couple of years ago, I used to produce regular mailbags, where I answer reader questions about whatever seems interesting to them. Today we're going to do that again. Despite the fact that this is being published on April Fool's Day, I'm not going to post any idiotic jokes, pranks, or lies herein. These are all actual questions from actual readers and actual answers from actual mes.

Additionally, since I am not employed by any teams right now, we get to talk about transfers and I get to say whatever the hell I want to, regardless of whose plans it might screw up. I can see the world's recruitment analysts and technical scouts wincing already. This should be fun... Here we go!

Who should Arsenal buy as a CM/DM for next season?

A lot of this has to do with who do you think needs replacing and why. Most people asked for a defensive midfielder, but seemed to want passing range and versatility. That is a tough combination to come by, and I think the rumored Granit Xhaka is rather good. However... if I am buying one central midfielder in Europe right now, it's Naby Keita.

Need a DM? Naby Keita.

Need an 8? Naby Keita.

A 10 that scores, creates, and destroys? Na-bee Kay-tuh. (Last time I did a bit like this, it was about Ivan Rakitic replacing Steven Gerrard before there was even a whisper of Rac-attack moving to Barcelona, so you know I am deadly serious.)

Just 21 years old, he played as an elite defensive midfielder in a pressing system last season.

This season he moved forward into an 8/10 role and has put up outrageous scoring stats while losing very little defensive output. No one does that. Only 1.72m tall, Naby is both fast and strong and has excellent balance. He's an outstanding dribbler. He's honestly one of the most athletic young central midfielders I have ever scouted.

The only question is whether his touch passing fits in with Arsenal's style well enough for Wenger to pick him. I think Arsenal need more of this type of athleticism in their squad for certain matchups, and this guy is wildly talented. I have been keeping track of him for quite a while now. At my old job, we [hit by electrical shocks]. So yeah, if I have to pick just one guy to fit in midfield for Arsenal, it's probably him.

What Manager Should Chelsea Hire? What Center Forward Should They Recruit?

The answers to this one are really boring and I apologize for that ahead of time, but these are the questions you gave me! I think Conte is an exceptional head coach who created utterly dominant teams in Serie A. The only real question is whether he can get players to buy into his methodology. I have information from very good sources that he is seriously intense. So is Diego Simeone. Those are my top two choices for manager, and I think Conte is far more likely to end up in London next season.

Can either of them win over the players and get the maximum out of them without losing the whole squad like Mourinho did?

As for a center forward, it's hard to see Chelsea improving much on Diego Costa and Bertrand Traore. I think Traore is one of the best young CFs in Europe and just needs some game time to adapt to the Premier League. I guess they could buy back Romelu Lukaku for twice what they sold him for (ouch), but barring that... Oh, and someone else said Chelsea need a new center back. The good news is you already own the guy I would probably recommend for you - Andreas Christensen. The bad news is that he's allegedly on loan to Gladbach for another season after this one.

What Goalkeeper Should Liverpool Buy?

Sorry folks, stats don't work on goalkeepers. Okay, that's not entirely true, but they only sort of work on GKs and I don't quite have enough time to answer this properly in full. Instead I'll just say they should buy Naby Keita for the midfield and that way whomever they do buy to compete with Mignolet next year will probably have less work to do. That's assuming Arsenal and Spurs don't buy him first. And let's be honest, assuming Arsene Wenger is not going to buy a central midfielder in the summer has been a safe bet for a very long time now. He's probably a more natural fit for Liverpool or Spurs than Arsenal anyway.

Who would you pick - Vincent Janssen or Sebastien Haller?

This is like making me choose between my kids. For those who don't follow the Eredivisie, these are two of the top young center forwards in the league. Do you know that Haller was bought by Utrecht on an option from Auxerre last spring for only 800k Euros? And bigger clubs than Utrecht wanted to buy him both last summer and in January and pay him a LOT more money, but he stayed put.

Rumor in the Netherlands is he only has eyes for Ajax right now, but I could see bigger fish with more money testing his desire to stay in Holland. I could also attempt to tell you an awful lot more about Haller and explain why I know a lot more about him, but that would trigger additional electrical shocks and I'm still kind of jittery after the last batch.

Meanwhile Janssen is one of the top scorers in Europe this season. A physical shot monster, I'm not sure about his pace, but he certainly causes huge problems for Dutch defenders. A couple of scouts I trust have also insisted he's the real deal (stats suggested this was likely months ago), and from what I have seen they are probably right. I would say Haller has a bit more potential and creates a few more goals for his teammates, while Janssen is a tremendous goalscorer right now. For me, Haller wins by a whisker, but it's basically too close to call. (And in the end, it all comes down to price and what the player wants to do anyway.)


This is an interesting question, and the real answer is that no one actually knows. I suspect Arsenal are probably furthest along in football research and they should be, as StatDNA had the biggest head start (outside of the Bolton group that dissipated). I have met a number of Arsenal's top level people on the analysis side and they are wicked smaht. It is annoying when your favorite team is also the team that would need your skill set the least, but thems the breaks. Liverpool are somewhere in the "we develop new football research/tech" sphere.

They even have a Director of Research, so something must be happening there! That's pretty much all I know. Southampton and Spurs probably have some cool stuff going, but I don't know enough about either place to say what. City is really hard to tell what is getting generated and what gets used, but they do have some personnel working on it. I don't think Chelsea or United have been developing anything on the analytics side for some time. Leicester City are doing smart things, but how much of that is related to stats research versus how much is just nailing normal decisions is something I am on the fence about.

But... and this is important... I could be totally fucking wrong.

All this stuff is supposed to be secret. If you are developing edges inside a club, you should NOT be talking about it. That makes it a whole lot of guess work on my part to say who is doing what well. I know we had some things at Smartodds that I was very happy with, and that I am pretty sure are bleeding edge tech (not just cool visualizations), but I can't be totally certain no one else developed those ages ago and simply didn't talk about it.

Our research was developed with a little over a year of full-time access to the Opta database and about two man years worth of output. *light bulb switches on* Funnily enough, I no longer work inside a club, so if Chelsea or Manchester United wanted to find someone smart who COULD talk about cutting edge research and what it could do for them... *makes the "call me" motion* The reason why I am talking about what clubs may or may not have developed is because that's the baseline for state of the art. Some things public analysts have going for them are as follows:

  1. You can collaborate and make each other smarter. Clubs can't do that except by hiring people from the outside, and they can never do that in scale. I'm not sure if you guys are the vehicle Voltron or the lion one, but you can certainly join together and fight space dragons and shit.
  2. There are lots and lots and lots of you. Teams have a comparatively tiny number of analysts and most of their brain is likely occupied by day-to-day tasks like how to beat Alan Pardew.
  3. Many of you have fascinating and unique skill sets to bring to bear on any number of football-related problems.

And some things that public analysts have going against them are as follows:

  1. Poor access to data and what you have is probably poorly organized unless you are a data/code pimp. If you are a data/code pimp, then you probably spent a lot of time getting your data organized and not doing any analysis or coding new tools or having any fun or...
  2. Everyone is learning from scratch in most cases and there is no clear path to accelerate that. Those who might create such paths are disincentivized to do so. Constantly recreating the wheel is costly when it comes to edumacation.
  3. Almost no one does this full-time. Or even half-time. It limits depth of expertise in the subject matter.
  4. No one has access to all the cool tools you can build which really can accelerate knowledge growth.
  5. Some of these club analysts have access to sweet proprietary data that only exist inside those clubs! The bastards.
  6. Top clubs have big budgets that they could spend on this if they saw the value. *again with the "call me" motion (*

Seriously, if I couldn't walk into any non-Arsenal, non-Liverpool club at this point and introduce them to a single competitive edge that could get them a minimum of 3 extra points a season (which equate to millions of pounds in revenue depending one where a team ends up in the table), I would hang up my analysis boots right now. The advantage left on the table OUTSIDE OF RECRUITMENT is fuck-ing massive at nearly every football club in existence. (Says the person who was just made redundant by a football club. Well, two of them, actually.)


I know it sounds incredibly arrogant or mildly insane that someone who no longer works at a Championship football club believes these Champions League clubs are missing out on enormous competitive edges, but that's exactly what I am saying. My work and reputation at this point is pretty solid, right? You guys trust me not to bullshit you at least a little bit? So you understand there is no way I would insist this to be the case unless I absolutely believed it to be true, and could damn well prove my case in private to people who wanted to listen.

I don't know everything. Hell, I barely know anything. As a whole, we know the tiniest bit about how football works. But that's the thing about sports - it's not about knowing everything, it's about understanding more than your competition. The thing is, once you start looking at these competitive edge problems with the right perspective, you notice improvements all over the place just waiting to be exploited. I dunno man... I assume the guys who figured out on base + slugging percentage were shocked no one else was exploiting it. So did the ones who developed the 3-pointers and drives offense in the NBA.

As did the guys who developed the spread offense in American Football, and countless other sport innovators. Hell, this is the epitome of Bill James' early and middle career. That's kind of where I'm at about all this stuff right now. (No, I did not compare myself to Bill James. He's a legend and I'm just barely getting started. I'm just saying he had an awful lot of knowledge that no one inside the sport really paid attention to for way too long a period of time.)

And the funny thing is, [SO MUCH REDACTED ELECTRICAL SHOCK TREATMENT]. Manchester United copying a single set piece (badly) is the tip o' the fucking iceberg, my friends. Back to the question at hand, I think certain public analysts are creating new things or at least derivative work that is really interesting. So some research might be state of the art. I am definitely not one of those people who think everything has been done already with event data.

In fact, I think we've barely scratched the surface of possibilities there, and I say this as someone who has done an awful lot of scratching. Of course, whenever a public person introduces new material, there's a chance it gets absorbed into the club IP sphere without so much as a thank you, but most people seem to do it as a-fun-hobby-that-could-eventually- some-day-in-the-far-distant-future-possibly-lead-to-a-job-that-doesn't-totally-suck? Do this stuff for yourself.

Make sure you are having fun with it, or go do something else with your free time. And if something happens, great, but don't wait by the phone for that girl to call because there are no girls who actually work in European football. Well, except Sarah Rudd, who happens to be one of the top people in the world in this area.

So if you are a girl, there is still hope that you can also be totally awesome and work in football! And then there would be two of you... Or three, I guess, if we count Marina Granovaskaia at Chelsea. Who I have not met but by all reports is also awesome. But I digress! (And I am clearly going to get in trouble with this, so it's probably time to move on and cut my losses.)

Two quick throughts before I answer other questions. I have run across multiple club owners and directors of football in the last year who have no idea what an expected goal is. Or a shots model. Or almost anything else to do with football stats and data. And these were definitely smart people I was talking to. I mention this not because I was surprised, but to detail a tiny piece of knowledge that people who are in the analytics community take for granted, but which has almost zero penetration beyond this particular football niche.

You don't need to know about expected goals to succeed in football. It helps. When applied correctly, it can definitely allow you to make smarter decisions. But the fact that Arsene Wenger mentioned it once in a press conference and you once-in-a-very-rare-while see it appear in mainstream media does not mean the concept has disseminated among the masses, either in fandom or by those employed in football.

This also relates back to why I think first mover advantage still exists and is enormous. The second anecdote goes back to this excerpt from "The Arm" by Jeff Passan that appeared on Yahoo Sports earlier in the week. That part of the book is awesome and you should read it. Kyle Boddy is the guy developing high velocity pitchers that gets profiled in that piece, and he's been a friend of mine for over a decade now. We've been grumpy old men on the internet together since well before either of us were of an age to be considered old.

We have always been grumpy. Anyway, he's a genius, but this isn't about him, it's about this bit further down.

"The Dodgers were run by Andrew Friedman, the hyperintelligent president of baseball operations who had just left the Rays after a decade-­long run of success. In Los Angeles, no budget bound Friedman. The Dodgers had just started an $8 billion local­-television contract that allowed their annual payrolls to threaten $300 million. Even better, Friedman and general manager Farhan Zaidi were allowing Fearing to build baseball’s biggest, best think tank. They were seeking experts in quantitative psychology and applied mathematics."

That's where baseball is right now. The only way to win more consistently is to be smarter, even when you have one of the biggest budgets in the league. And yet the excerpt from Passan's book goes a very long way detailing how backwards and wrong baseball have been about development of pitchers for the last decade (and longer). So much of the accepted conventional wisdom was completely and utterly incorrect regarding the most valuable position in the game. Now think about football, which is arguably twenty years behind where baseball is right now.

How much advantage is there for a club who sees a glimpse of the future, has the brain trust and money in place to invest in finding smarter ways to do things, and has the decision making structure to exploit the new intelligence that is discovered? In no other sport in the world do clubs control so many elements they can use to create advantages. Football clubs have access to academy players when they are children.

In the United States, they almost never get access until they are 18 or older. Football clubs also have the potential to completely revamp their roster on a yearly basis if they want to. None of the U.S. sports can do that. Also unique is the worldwide access to talent via the transfer market, and the fact that more people in the world play football than any other sport. Advantageous styles of play. Tactical edges. Better players, for cheaper prices.

Better coaches. Better, different training.

The potential for discovering and leveraging marginal gains for performance improvements is astounding, and this is not pie in the sky stuff. These are things that have been delivered successfully time and again as other sports grew into their analytical ages. But like my wish for a media provider that sees the value in people flocking to their site to generate radars and shot maps on the daily, this vision of what's possible in football is nothing more than a dream that you hope someone with power or influence or money eventually turns into a reality.

That is a project I would like to be a part of. Moving on!


You know how everyone always says that the real strength of using data in sports is to help teams avoid making stupid mistakes? Someone introduce Boro to the concept. Don't get me wrong, they have a great head coach - the hardest position to recruit - and they are lurking right at the top of the Championship again.

That said, their value for money in the transfer market this season has been poor, and the wages they pay out... woof.

It's weird for me to say this, as I have written publicly about Rhodes being a very interesting and sometimes undervalued striker in the past. The reason my tone has changed is because his data changed. After being one of the best forwards in the Football League for almost half a decade, he's now posting below average numbers.

This is a big red flag, especially when it comes to forwards, and double especially when it involves a monster £9M fee plus add-ons plus wages. It's too early to say this is a mistake, but there is an enormous amount of risk attached to it. Risk that Boro will happily deal with and/or write off, should they finally make the promised land of the Premier League.


Spurs centerbacks last year was a huge clash. Actually, given they had AVB before, it's weird that Spurs still had CBs that were slow and completely incapable of playing a high pressing style even through last season.

They solved that problem really well this summer. There are countless examples you could roll through - from an unsuitable Mario Balotelli trying to fill a Sturridge/Suarez role at Liverpool, to crossing wingers being added to possession teams, to purely defensive fullbacks being added to teams that need dynamic over- and under-laps to unlock teams in the final third.

Recruitment is tricky in the best of circumstances, but it absolutely must start with a clearly defined style of play that you can then fit players into and around. And it needs a coach who can coach that style of play, or your team is likely to end up in real trouble.


I did not.

I did manage to get a picture with it, which ended up being really important to me because in this business it is so easy to forget your successes. I was lucky enough to play a tiny role in a team winning its first league title and making the Europa League knockout stages. Given that I started all this when I was on chemo, the day FCM held their trophy celebration meant a lot to me. I still get goosebumps when I watch the video.


The reffing might be the biggest single difference between the leagues. Lack of called fouls make it a lot harder on skill players, and you definitely focus a bit more at body type when scouting, so that players can have more durability in the Championship.

That said, some fitness guys go too far in having players put on muscle at the expense of actually being able to play football, so there's a balance there. People don't perceive it this way, but there is probably only a small difference in quality of play between the bottom half of the Premier League and the top 6 to 8 teams in the Championship. Plenty of Champ teams now go up and stay there, especially if they have good coaches. Swansea, Southampton, Watford, Bournemouth, and Leicester are all archetypes of clubs that not only go up, but who can perform pretty well once there.

Off the pitch, I think the facilities are tremendously different, especially at the sides who have been established in the Premier League consistently. Then again, most of my time has been spent at one of the lowest revenue clubs in the Championship, so maybe other clubs are way more posh than I expect. The last thing I think is very different is the quality of head coach or manager. The foreign influx in the Premier League, has been enormous, even more than with the players, and as of next season it will be absolutely loaded with top coaches. I think the Championship is still a bit behind that right now, but we are seeing more foreign coach recruitment there as well, so it may not stay that way for long.


True story: I was watching set piece training, and comparing it to what I saw at FC Midtjylland.


Maybe some day. Here's the thing - you only get so many minutes on a training pitch each week. And yet you have a ton of things you need to teach players about the next opponent, about their own performance, about how they need to develop... about everything. I think at most clubs, the usage of coach analysts is a great way to bridge this gap, from young players through the first team. And at most clubs I don't think this is happening, at all.


Very little, but it does depend a bit on culture/country. I think player capacity for learning is hugely underestimated, especially in England. That said, you need to be really careful with what you introduce and how you introduce it. If I were starting somewhere new, I would do this, but very gently, and I would go out of my way to find out who would likely be receptive ahead of time.


This is funny, because we actually looked at this in detail at work, but it was with Andros Townsend in mind instead of Coutinho. I don't want to ruin it because I still plan to use Townsend in a future presentation and article, but I will say that Coutinho's average shot is about twice as good as Townsend's.

(This assumes that my script isn't horribly bugged, which is not a guarantee right now.) Philippe Coutinho_2015-16

While on this topic, two more fun facts from the Opta data set. First, Bayern's lightning quick wide player Douglas Costa clocks in at around .05 xG per shot average, which is startling for a Pep player and explains the whole two goals in 1700 minutes thing for him. Second, Alessandro Diamanti (briefly of Watford this season) had the worst goal expectation per shot of any high volume guy we looked at back when we were arguing at work. There was one season where his expectation - and I am absolutely not exaggerating this - was about one goal in every 40 to 50 non-penalty shots.


James already knows I am going to say player evaluation and transfers. People love to read it, which in turn means more people will be reading smart data pieces, which HAS to be a good thing, right?

I also think a lot more people should poke around in the same areas that Dustin Ward and Thom Lawrence have been researching (click their names for links to the articles). Their stuff is very smart and as cutting edge as it gets. I'd suggest more people follow in the footsteps of Will Gurpinar-Morgan and Martin Eastwood, but I am pretty sure the education and skills required to do so would be a massive hurdle for just about anybody, myself included.


Five years is a long time, and it's hard to stay dumb that long about transfers and stay in the Premier League unless the team is unconscionably rich. I think Arsenal rarely make mistakes in who they buy, so they probably win the award for most impressive.

On the other hand, I think they frequently make mistakes with who they don't buy, or who they sign to new contracts, but those last two things are almost entirely down to Arsene Wenger. I think Chelsea waste a ton of money every year buying confusing players that are highly unlikely to succeed, but they do have some fairly high profile hits as well. They also have a gigantic portfolio of player assets out on loan that could potentially benefit from better management.

Overall though, things aren't that bad there. United have been really poor at signing new players right up until this past season, when they got smart really fast. I think they found a source of good advice in the summer that directed them to good players, even if they seemed to dramatically overpay in almost every instance. It's been really difficult to see a consistent plan at Liverpool.

In fact, from the outside their recruitment has often looked like two rival factions, each getting half the players they wanted and then attempting to assemble a competent squad on the pitch. That seems sub-optimal, but who really knows the truth? If I had to pick one long-term PL club that has shit the bed consistently with regard to transfers over a five-year period, it has to be either Villa or Sunderland. Given the money spent, I'm pretty sure Sunderland win this one by a nose. (And to be fair to them, Villa had so much dead money immediately after the Houllier era, they actually couldn't spend any more and are still digging out of that hole.)

I don't know what happens behind the scenes there, but the recruitment in that place has been horrific for just about as long as I can remember. Finally, if I'm picking a club terrible at recruitment that used to be in the Premier League but isn't any more, it's probably Fulham. From Europa League final in 2010 to 21st in the Championship as of right now. Someone needs to pull the cord there, and soon, or they will follow Wigan and Wolves plunge from the Premier League to League One in no time at all. Nearly 4500 words of blathering, all in response to questions by you.

My wife assures me that I am absolutely, positively going on holiday next week, which means no new content from yours truly on the site. Thankfully, since there is actual football on television this week, James and company will be back and better than ever. Even though I had to lose my job for it to happen, I have really enjoyed being able to write about football again this week, and I hope you have enjoyed reading it.