Author: Kevin Lawson

What does a football analytics company do on slack on a Thursday afternoon when there are no games to speak of? Why talk about basketball of course. Well, not just basketball. The question that arose was who would you pick to compete in a combined basketball and five-a-side match. That is, first the teams played football, then basketball, then if they split those two matches, they'd have a shootout to as a tiebreaker to determine the overall winner. Ultimately we decided to make draft lists. So, four StatsBomb experts (I use the term extremely loosely here) made their top ten lists of who they'd like to run out on the the court/pitch for such a hypothetical competition, complete with their reasoning. So, down below you'll find the lists of CEO Ted Knutson, StatsBomb South head honcho, Ali Elfakharany, CCO, Shergul Arshad and general man about analysis town, Euan Dewar. You should feel free to find all of them on twitter and tell them why they're wrong. Also feel free to figure out your own teams and tell us why you're right. And now, without further ado, the lists. Ted Knutson

2) Giannis "The Greek Freak" Antetokounmpo I think a lot of people will have Giannis as their number 1, and it just makes sense. He's definitely in the top 5 NBA players in any particular year and he's at least had some exposure to juggling the ball. However, having seen enough clips of him interacting with a soccer ball, I'm fairly comfortable that Embiid is the better number one overall.

Ali Elfakharany Despite the fact that the tiebreak is football-related, my train of thought was to mainly pick basketball players for a couple of reasons:

• Football is more popular globally so it’s easier to find base level football skills
• Basketball is more unique physically and so it’s harder to find basketball physique!
• Big basketball players might make good goalkeepers for the shootout
• Absolute domination matters for mental purposes
• Most StatsBomb folks don’t know basketball as well as I do

Without further ado, my list: 1) Joel Embiid The Process is the perfect fit for this sport. A 7’2 foot center with the best low post moves since Hakeem, who is also a magnificent trash talker that grew up in football-crazy Cameroon? Sign me up. Jojo will dunk all over these tiny footballers, and trash-talk them so badly all their penalties will look like that famous Sergio Ramos penalty that ended up orbiting the moon. And he may foul out the entire team before we even get to the shootout. Joel is also the most entertaining guy in sports, and he’ll make sure we have no problems selling this event out. Just think of all the Spanish/Portugese he’ll learn just to mess with Cristiano and Messi. If you need visual evidence, a quick Youtube search will show his spot-kick prowess, https://www.youtube.com/watch?v=X27obRcPLFI and him driving poor Andre Drummond crazy with his antics. https://www.youtube.com/watch?v=miN7g6iEmeo 2) Giannis Antetokounmpo The reigning NBA MVP and probable best player in the world is another obvious pick. African heritage but born and raised in Europe sounds like a football star (Zidane, Mbappe) and a quick Youtube search shows the Greek Freak has some serious football skills. Giannis will bring his trademark enthusiasm and competitiveness to the team, and will probably spend the entirety of the competition mean mugging all these soft European football players. 3) Romelu Lukaku 6’3 and heavier than Russel Westbrook – will be able to keep up physically in both sports. 4) Luka Doncic Luka’s IQ, footwork, and skill ability translate beautifully between both sports. He will reign threes on the football players all while looking very relatable athletically, and then bust out a couple of penalty saves with training from his countryman Samir Handanović 5) Pau Gasol Friends with a lot of football players 6) Zlatan Ibrahimović 6’5, a kung-fu background, supreme ball skills and the OG football trash talker. 7) Antoine Griezmann Obsessed with the NBA and seems to have a 3 point shot 8) Pique A very tall and skilful football player with connections to other sports 9) Pierre-Emerick Aubameyang https://www.youtube.com/watch?v=SPQQRwD3j9A 10) Cristiano Ronaldo https://www.youtube.com/watch?v=AunImole9HI   Euan Dewar My assumption is that a team of all-footballers/all-basketball players would decimate any opposing team that has even one player who is not playing their preferred sport. The basketball players aren't going to suddenly all turn into Ronaldinho, the football players aren't all going to start hitting three-pointers against NBA-level defence (or even in an empty gym). If this didn't have the penalty shootout aspect I would have gone with solely NBA players. My thinking is that it's extremely hard to imagine footballers lucking in to even a few buckets against a team of NBA players, but a team of NBA players maybe nicking a goal in a 5-a-side, I think that's easier to imagine. Think of Lebron James trucking some dude off the ball and then finding Russell Westbrook with a pass who zooms down with it and scores. Not super likely, but you can see it happening right? Only there is a penalty shootout involved here, so I'm punting the basketball side and going with only football players. Penalty-taking is a relatively simplistic skill in raw terms - you have much less to consider than you do in open play. But it is still a skill where you can see differences in execution across various levels of talent. NBA players, while immensely gifted, are still miles off of elite footballers in performing football actions. Therefore I want the best footballers so we can crush them in the football match, knowingly get our arses handed to us in the basketball game, and then breeze through the shootout. The more weak links we have (i.e, NBA players) in that segment the worse off we'd be. 1) Lionel Messi Obvious choice. Ironically, he may actually be a weakness in the shootout given recent penalty history, but I am assuming that wouldn't be a huge problem in this scenario. 2) Jan Oblak To truly tighten the noose, a wall of a goalkeeper is also needed. Instead of picking a goalkeeper with a noted penalty-saving record (alhough I will do later) I'm going with probably just the best shot-stopper around. Trusting too much in penalty-saving sample sizes when selecting for this seems foolhardy. Also maybe he can get a layup, who knows. 3) Virgil van Dijk Has all you need in terms of awareness and physical traits to shore up the defense, all while being lovely in-possession too. 4) Kylian Mbappe Good luck. 5) Arturo Vidal My one fear in the football match is that a given NBA player of the requisite size could just ease smaller footballers off the ball (especially if this is FIFA Street rules). WIth that in mind, a big enforcer is needed. VvD fills a big chunk of this need. Vidal is past his prime but still has plenty of skill and, importantly, is a combative bugger with the build to back it up. 6) Josip Iličić Why not make the whole plane out of Messis? 7) Idrissa Gueye Could also absolutely tear shit apart. 8) David de Gea Slumping as of late but no reason to believe as of yet that it's a permanent drop-off. Probably still unbeatable in this environment. 9) Robert Lewandowski If I were to go with a purer-striker it'd have to Lewy. 10) Simon Mignolet Apparently he has a good penalty-saving record on a bigger sample size than most other goalkeepers. Maybe that means something. If not, well I feel he is owed some slack for all the abuse he has received over the years. Namaste.  

Last week Kirsten Schlewtiz and I talked about the basics of football analytics. We had so much fun that we decided to do it again this week. Specifically, we’re going to talk through what it’s like to use stats to analyze a player. What it adds, what it misses, and how best to understand what’s going on if you’ve never seen a number that didn’t give you flashbacks to failing a test at ten years old. So, take it away Kirsten.

KS: Mike, personally I had to pass AP stats to graduate high school and I’m still not sure how I did it … likely something to do with those giant TI-85 calculators and a notecard hidden inside the case. Anyway, we want a player to talk about. There’s the top two in the world, but that’d be boring; besides, Lionel Messi has been covered exhaustively on this site. We could analyze the Borussia Dortmund teens, but being a Gladbach fan, that’s too big a reach.

So let’s go with Timo Werner. He’s fast, he’s capable, and he’s helping light up the league with RB Leipzig. But those who have seen him with the Germany national team only likely have more disparaging words to say about the attacker. So what’s the first statistical value we can use to establish his dominance?

MG: Werner’s a great place to start. For a bunch of reasons. Our go to stat for strikers is expected goals per 90 minutes played. We do that for a few reasons. First, we want to look at expected goals and not actual goals because finishing is very noisy but getting good shots is a pretty consistent skill. That’s not to say that individual players aren’t good finishers, the best strikers in the world as a group do tend to average a little higher finishing than a model would predict, but that’s a relatively small part of the picture. The majority of what separates the best from the rest is their ability to find and take lots of good shots. Then we look at it per 90 minutes played because we want to be able to compare players based on what they do when they are on the pitch. You’d rather have a player that plays most of the game and scores a lot of goals than one who plays absolutely all the minutes but only scores a little bit more. So, on to Werner. He averages 0.59 xG per 90. That’s really good. Of players who have played over 900 minutes, only Robert Lewandowski is better, though he’s at 0.79 which is kind of a “break the game” obscenely high level. Does that all make some semblance of sense?

KS: You say we should first look at expected goals, but despite being with StatsBomb for nearly six months, and recognizing the importance of that stat, I still don’t know how you arrive at a player’s xG. I assume you don’t just have a bunch of drones watching that player and inputting their thoughts about when they should score a goal, as opposed to when they actually do. So how is it calculated?

MG: So the way the stat works is it takes tons of factors into consideration and then measures how likely any individual shot is to become a goal given those factors. Start with the location on the pitch, and see how many of the thousands of shots we have go in from there, then keep adding in factors like what part of the body the shot was taken with, what kind of pass led to the shot, was it a set play or not, where were the defenders at the time the shot was taken (a feature unique to StatsBomb data). Then do some fancy math to make it as accurate as possible and you have an xG model. The thing about these models is that they aren’t all that useful when looking at an individual shot because individual shots can vary a lot. But, when the shots start to add up you get a pretty accurate picture of how often a player or team will score.

KS: Focus, Mike — we’re leaving teams for next week. So turning back to individuals, how many shots would you need to come up with a decent estimation? I’m going to assume there are certain players you just wouldn’t have a reliable xG for, such as goalkeepers, but I’m guessing there’s a cutoff point. And Timo’s clearly made that point, as evidenced by you saying his xG is really good . . . but given you don’t mention an average xG, then we need to both take your word that there is a number of shots that should be taken, and that Timo’s number is high enough for him to be measured and come out looking quite grand.

MG: Good question! There’s two ways to look at that. If you’re asking how many shots does it take to ensure that xG is faithfully representing how many goals a player should have scored from the shots he’s taken, the answer is very few. That’s because an xG model is built on all the shots that everybody across the sport has taken. Though to give you a specific answer I’d have to point to things like confidence intervals, and such, and I don’t want to give you flashbacks to high school. The second way to interpret the question is trickier, because if you’re asking how long before we know that Timo Werner’s xG per 90 so far this season of 0.59 is what his xG will continue to be in the future, well we don’t have a good answer for that. Individual stats are contextual and lots of things can change. For example, young players get better. Werner is 24 right now and entering what we’d anticipate to be his peak performance years, but there’s a considerable amount of variability in how any individual player will develop. He’s great now but does that mean he’s done getting better or there’s more to come? And even if his skill level is done improving lots of other things can change. He could change teams, he could get injured, the division of his minutes between the wing and striker could shift dramatically. He could decide that he really likes ice cream and doesn’t like to exercise. The universe is vast and the future is unknowable. So, why use xG at all then? Because even though we can’t say with certainty what the future holds, we can say that xG is better at explaining how good Werner is now, and how good he will be in the future than actual goals scored is. It’s true that his xG might move around a lot in the years to come, but it’s simply better at predicting how good he’ll be than his actual goals scored number. To that end, he’s scored 0.88 goals per 90 this season in the Bundesliga, so we should expect that his xG is a more accurate representation of what he’ll be going forward than the goals.

KS: Actually, what I meant was how do we know that 0.59 is very good? Apparently, I need to work on writing clarity.

MG: Well that one’s easy! You know it’s good because it’s the second highest in the Bundesliga. Also, conveniently it lines up with the “goal every other game” common wisdom about strikers that has floated around forever.

KS: You mentioned his division between winger and striker. I feel like he hasn’t performed well for the German men’s national team because he’s been alone up top. I know StatsBomb has limited national team stats, but I’m sure that even without those, there’s a way to use stats to either affirm or deny my assertion that Werner just doesn’t function as well in that role. Am I right?

MG: It’s actually more difficult to parse that out than you’d think. It’s definitely true that he struggled at the World Cup in 2018 where he only averaged 0.22 xG per 90 minutes while playing two-thirds of his time as striker. Is it because of something he’s doing as a forward? Is it because of how Germany elected to play as a team? Is it because three games is a tiny sample? The answer to all those questions is maybe. But one thing it’s worth noting is that Werner is himself much more than a pure goalscorer. And even during a disastrous World Cup the other stuff he does stands out, He actually assisted almost as much xG, 0.20 per 90, as he attempted himself. And those other statistics are something that make him stand out during club play as well. In addition to being a great goal scorer he’s a great creator, a feature of his game that persisted at a national level even during periods where his goal scoring seems to have abandoned him.

KS: Ugh, Mike, you took my next question; it was meant to be about more than Werner’s goalscoring abilities, and assessing him as an all-around attacker. So let’s talk about speed. To my semi-trained eye, Timo appears quite quick on the pitch, allowing him to link up with his teammates up front. You’ve already mentioned he’s able to provide assists (although feel free to tell us the statistical term used for that, along with his numbers for RB Leipzig thus far this season), but is there any way to measure just how fast a player is?

MG: So, it’s deceptively difficult to measure the actual speed a player is running at, although teams can do things like make players don wearable technology to help with that kind of thing. But, for our purposes we’re looking at the things that enable performance on the pitch. So, for example, we can look at a shot chart from Werner and look for all the shots that come as a result of him receiving a throughball (the little triangles).

Or we can look at where and how he’s receiving certain kinds of passes. Below are all the passes he received in the attacking half which originated in his team’s own half. And what we can see is that he consistently peels off to the side — usually the left — and receives balls, the pattern of a player running the channels as a speedster rather than one who is a more central physical target man.

These are all somewhat indirect ways of using the data to get at the underlying reality but they paint the picture of a player whose speed is a central part of his game.

KS: Ok, I think one final question should cover both my impressions of Timo, and the use of numbers to really parse out an attacker’s abilities. Being a big Bundesliga fan, he’s been on my radar for awhile, and it feels to me that while Leipzig as a team have improved considerably in the last few years, Werner’s passing in particular has also improved. Are there any stats that back up what I think I’ve been seeing? MG: Well, RB are an interesting case as a team, since they arrived in the Bundesliga under such unusual circumstances and qualified for the Champions League their first season there. But, I’m not supposed to be talking about teams. Werner himself has certainly improved. Maybe the easiest way to show it is to just do a visual representation of his collection of stats last season vs his collection of stats this season?

The radar shows how he’s doing basically the same things this season that he did last season,.but a lot more of them. How much of that is him developing as a player, and how much of that is his team improving? That’s something that is as much art as science to diagnose. So, the answer is that he’s playing better this year than last and his team is as well, but those two facts are difficult to disentangle. That seems like a good place to leave things for now, although there’s always a lot more to cover. We haven’t even touched on xG per shot or set pieces, or any of the other ways we profile how a striker gets their xG. But that’ll just have to wait for another week.

The world might be upended by coronavirus but the Champions League is set to march on. So do we with our previews.

RB Leipzig v Tottenham Hotspur

The good news for Spurs is that they’re only down a goal. The bad news is that Leipzig were very good value for the away goal they scored. Spurs' problems have been well documented over the past month, with the side basically giving back all of the performance gains that new manager José Mourinho initially brought with him The team's injury crisis is apparent with January signing Steven Bergwijn joining Harry Kane and Son Heung-min on the sideline. Domestically, especially against teams with less talent, there’s room for debate about whether or not Mourinho could make certain tactical choices to get the most out of his remaining squad. Against Leipzig, however, the team is in a bind. With so few healthy attackers, and no true forward to speak of, Spurs simply cannot execute Mourinho’s desired approach of bending but not breaking and then counterattacking at lightning speed. They have no one to counterattack through. Conversely, if they try to hold the ball against Leipzig, they'd have both trouble moving it up the field and a lack of presence in the box to act as a focal point. Meanwhile, they’d expose themselves to a lightning-fast and efficient counterattack from the German side. Meanwhile, for Leipzig, while it’s the team’s attack that often garners attention, their defense is what will likely be on display as they attempt to see out the tie. And the team defends very very well. They’re a classic shot-suppression side, conceding the second-fewest shots in Germany. Leipzig want to defend far from their own goal, and to force teams to beat an aggressive press to create chances. That’s why this task is so daunting for Mourinho. He’s a manager that normally is happy to play against an aggressive pressing team. He wants to invite pressure and then beat it through the combination of a target forward and a speedy attacking winger executing fast and efficient counterattacks. Unfortunately for Spurs, their target forward and fast creative winger won’t be playing. For Tottenham to have a chance at staging a comeback they'll have to solve the exact problem that’s been hounding this side for weeks. They’re going to need to break a press without press breakers.

Valencia v Atalanta

Sometimes there are more important things than sports. And for the northern Italian side this is one of those times. Amidst the coronavirus crisis, the squad has played only one match since beating Valencia 4–1 at home on February 19th, breaking apart Lecce 2–7 on the first of the month. The good sporting news for Atalanta is that they have clearly been the better side, and they travel to Valencia with quite a cushion after their 4–1 victory in the reverse fixture. Valencia do have something to hang their hopes on though, and it’s that the first leg wasn’t nearly as lopsided as it seemed. While Atalanta scored early and put the game to bed shortly after halftime, Valencia really did find a lot of attacking joy over the final half hour. The usual pattern of a match like this would be Valencia, trailing at home, would have a ton of the ball and Atalanta would try to defend against a desperate onslaught and put the game away on the counter. A number of famous comebacks over the last few seasons have followed this pattern and resulted in the trailing team getting a needed result. But neither Valencia nor Atalanta fit that mould. Atalanta are addicted to having the ball. And Valencia are one of the deepest defending teams in the world. If Valencia do stage a major comeback it would be because Atalanta simply don’t have the capacity to play cautiously and Valencia manage to take advantage three times. The team does have the fourth-highest expected goals per shot value in La Liga, so a comeback is not out of the realm of possibility. The most likely outcome is that Atalanta just keep on scoring and win this battle easily. The side puts up the kinds of attacking totals that any team in the world would be proud of. It’s hard to imagine they won’t put one or two past Valencia unless they end up confronted with a terrible finishing streak. Stranger things have happened, but there’s no reason to expect it. One of the challenges of analyzing this Champions League season is the fact that some teams are simply much better than their reputations. Atalanta tops that list. They’re just so beyond Valencia that it's hard to imagine them blowing this lead without a whole bunch of luck going against them.

One of the most useful things an analyst can do with a statistic like expected goals is find good attacking players who aren’t yet showing up on the score sheet. Players that either take high-quality shots themselves, or create them for their teammates, see those opportunities turn into goals eventually. Then there’s poor David McGoldrick of Sheffield United. Nobody is further behind their expected goal contribution per 90 minutes, defined as combined expected goals and expected goals assisted, than McGoldrick (among players who have played more than 600 minutes). McGoldrick’s futility is even more impressive when you take into account that he has actually assisted more goals than xG predicts. The struggling striker has two assists while he has assisted shots worth 1.26 xG. So, the entirety of McGoldrick’s league-leading struggles at scoring come from shooting. It’s ugly. Couldn’t hit the broad side of a barn with a beachball ugly. Sometimes, when a player is on a cold streak, it’s clear that the culprit is bad luck. Players that take a lot of long-range shots, for example, will often see dramatic swings in their performance against xG, pinging all around their expected level thanks to the nature of the shots they’re taking. A player who feasts on low percentage shots will occasionally see one go in, which boosts his performance against xG dramatically while also going long stretches missing all the hopeful punts he sends in the general direction of opposing keepers. That’s not happening here though. McGoldrick is actually quite savvy when it comes to shot selection. He averages 0.15 xG per shot, which is a fairly robust number. Among players who have taken more than 20 shots this season, he’s 17th in xG per shot. It’s clear from his shot distribution that he’s not piling on low expectation efforts from distance, he’s just getting lots of pretty good shots and missing every. single. one. How exactly is McGoldrick managing to pull off this trick? Well, if we pry apart his shooting numbers we see some interesting stuff (still no goals though). How exactly is he missing? One thing that appears to be happening is that goalkeepers are playing absolutely out of their minds against him. The post-shot xG value of McGoldtrick’s shots is 4.55 from 16 on-target shots. A brief nerdy stats note here. Post-shot xG doesn’t tell us very much that’s meaningful about the quality of McGoldrick’s shooting. A shot that fizzes just wide gets a value of zero and one that’s lollipopped softly into the keeper's arms will have a non-zero value, while the former may very well be a better attempt than the latter. So, the fact that the post-shot xG here is lower than regular xG doesn’t prove much about McGoldrick’s attempts. What it does show is that keepers seem to turn into gigantic multi-armed monsters against him, saving over four more shots than expected. When we get this granular, of course, there is always going to be some debate about who deserves credit for a great save, and who gets blamed for perhaps making the keeper's life easier than the numbers can detect. Those issues get averaged out with large numbers of shots, but when we’re looking at something like McGoldrick prodding a ball in the general direction of a gaping net, and Crystal Palace’s Vincente Guaita recovering to make a save, the question of sorting out exactly who gets credits and demerits for what remains an open one. Individual shots get missed all the time, for all sorts of reasons. It’s just that McGoldrick has missed so darn many of them this season. Four separate times he’s managed to kick the ball towards goal from inside the six-yard box, only to see two of them get saved, and two of them miss the target entirely. The good news for McGoldrick is that he’s almost certainly getting unlucky. Whenever something this unlikely happens, it’s at least partially down to dumb luck. The problem for him is that it’s also probably not just luck. McGoldrick is 32 years old. He’s played his entire career in the lower divisions of English football and never been a consistent goal scorer. While he scored 12 non-penalty goals last season from 15.20 xG (and an additional three penalties), he has not had a prolific goal-scoring career. Before last season he had only reached double digits in goals three times, in 2013–14 with 14 goals for Ipswich Town in the Championship, 2012–13 with 16 goals for Coventry City in League One, and way back in 2008–09 with Southampton in the Championship. All things being equal, we expect players to eventually perform to the xG. But, sometimes everything else is not equal. McGoldrick is a longtime journeyman of a striker. Suddenly at age 32, he finds himself playing at the highest level of his career. He plays for an extraordinarily well-coached team in Sheffield United, one that is exceptional at working together to create great shots. McGoldrick keeps missing those great shots. The simplest explanation is not that McGoldrick is facing exceptionally, historically bad luck (although we shouldn’t rule that possibility out entirely) but rather that he’s a player who just isn’t quite good enough for this level. Sheffield United manager Chris Wilder excels at getting the most out of his squad. That includes finding an aging striker with a preternatural instinct for getting on the end of his team’s highly choreographed creative attacking moves to create really good chances. When you’re Wilder and Sheffield United, however, you’re also shopping in the bargain bin, and that means perhaps the player you’ve found to do that just isn’t quite up to snuff when it comes to actually putting the ball into the back of the net. So, the bad news is that McGoldrick’s finishing struggles might not just be bad luck. The good news is that Sheffield United are succeeding this season anyway. The really good news is that this means there’s room for them to become even better. Just imagine what this team might do if one of their strikers wasn’t chronically unable to finish.

Crystal Palace are a wonder to behold. They are by any particular measure an absolutely terrible team. And yet, 23 games into the Premier League season, they sit comfortably at ninth place in the table. It’s always tempting to look for reasons why in cases like Palace. Surely, the numbers must be missing something. And yet, as seductive as the siren call of pattern recognition might be to the human brain, sometimes there’s no greater answer than that the soccer gods are really enamored with Roy Hodgson. You don’t need fancy stats to understand that Crystal Palace are an anemic attacking side. They’ve scored only 22 goals this season. Only relegation battlers Watford and Bournemouth have scored fewer. That scoring record is a fair reflection of their underlying performance. They’ve scored 19 non-penalty goals and have 19.10 expected goals. Their xG per match of 0.82 is only narrowly edged out by Newcastle’s 0.81 for the lowest in the league. The problems are obvious. Palace only takes 9.39 shots per match, the fewest in the league. Those shots are themselves valued at only 0.09 xG per shot, the third-worst average in the league. So, to paraphrase Yogi Berra: The shots here are terrible and there are so few of them. That’s simply a recipe for attacking futility any way you slice it. But wait, I hear you cry, surely their defense must be their calling card. Many a successful season has been built on a pathetic attack married to a stalwart, death-defying defense. And it’s true that, at least superficially, Palace is stronger on that side of the ball. They’ve only conceded 26 goals; that’s a great number. Only Liverpool, Leicester City and Sheffield United have conceded fewer. Wow! But here the advanced numbers are a little more useful. Crystal Palace give up a lot of shots. They concede 13.61 per match; only Aston Villa, Newcastle, Norwich, Arsenal and Bournemouth give up more. To their credit, those shots have been largely benign. The average xG per shot of those Palace have conceded is 0.10, a mark only bettered by Wolverhampton, Arsenal, Burnley, Tottenham Hotspur, Norwich City and Manchester United. Lots of shots conceded, but mostly bad shots can be a recipe for an acceptable defense, and that’s exactly what Palace have. Hodgson has his team playing as the 13th best defense in the Premier League with a non-penalty xG conceded per game of 1.33. Of course, that’s a far cry from having conceded the fourth-fewest goals in the Premier League. Enter Vincente Guaita. Want one weird trick for turning your somewhat below-average defensive side into the fourth-best in the league? Have your keeper play absolutely out of his gosh-darned mind. Guaita is single-handedly responsible for saving just below eight goals more than a keeper putting in an average performance might have this season. Add those goals back in and a Palace side that conceded 34 goals would be much less notable. They would, In fact, be awfully close to where xG predicts, with only five teams conceding more than them, and three others conceding the exact same amount. Clearly you don’t need advanced stats to understand how good Guaita’s been. He plays for Palace and Palace have been the fourth-stingiest team in the league defensively, which alone is a pretty wonderful advert for him. But those fancy numbers make it even clearer. Guaita’s save percentage isn’t all that impressive. At 74.7%, there are five other keepers ahead of him, so he's good but not exceptional. What really makes him pop, though, is that he’s faced an exceptionally difficult caliber of shot. In fact, given the shots he’s faced, an average keeper would only be expected to save 65.2% of them. He’s faced the third-hardest set of shots in the league, which puts the fact that he has the sixth-highest save percentage in an entirely different light. There is nobody in the Premier League with a larger difference between their save percentage and expected save percentage than Guaita. That’s the purest measure of how good a shot stopper a keeper has been. The 9.5% difference puts him ever so slightly ahead of Liverpool’s Alisson as the keeper who has been the best this year at keeping the ball out of the net relative to expectations. The problem for Crystal Palace is that there’s nothing that suggests Guaita’s remarkable season will continue. At 33 years old, the Spaniard has had a solid career, first with Valencia, then over four years with Getafe, before landing in London, but nothing that suggests the spectacular. Last year, his first with Crystal Palace, he was fine. Ironically, he had a very similar save percentage, 74.4%, but shots he faced were considerably easier, and had an expected save percentage of 72.2%. So, he was 2.2% better than expected in his time on the field—nothing to sneeze at, but a far cry from 9.5%. All of which is to say that the miracle of Crystal Palace stems primarily from their keeper, and their keeper, despite a long history of being pretty good, does not have a history of being miraculous. Sometimes it’s hard to pinpoint where and how the soccer gods are sprinkling their dust. Other times they just straight-up inhabit the body of a journeyman 33-year-old keeper. None of this should be particularly encouraging for Crystal Palace supporters, however. It’s great that Guaita sprouted tree trunk arms for twenty games, which was almost single-handedly enough to push them from relegation battlers to the top half of the Premier League table. Barring an absolutely astounding collapse they’ll remain in the top division to fight another season. But this doesn’t bode well for their long-term health. When those fickle gods alight upon somebody else’s body, Crystal Palace will be left with an anemic attack and a defense that isn’t nearly as strong as Guaita’s form has made it seem. That may not matter this season, but if they don’t figure out how to get better before the next, a relegation battle awaits. And there, but for the soccer gods, will go Crystal Palace.