Turning Theory Into Practice: Paul Riley Meets Swedish National Goalkeeping Coach Maths Elfvendal

Back in 2012, spurred on by my wife and a friend who out of boredom at work deliberately sparked daily debate with his outlandish football takes, I started blogging about football and using data to answer the questions it poses. Fast forward six years and what started as a mess about has become seriously surreal.

Twitter gets its fair share of criticism, but it’s enabled me personally to reach crazy great people. At first it was all about volume of traffic and gaining new followers. Soon, it became about more than that. I was invited back to my home town to visit Bolton Wanderers’ Head of Analytical Development, invited by the Scouting and Recruitment Co-ordinator of my beloved Everton to speak with him at Finch Farm. It’s still bonkers to me that people in the professional game speak to me, read some of the words I’ve written and listened to some of the words I speak. Following my StatsBomb come back in August the Swedish national team goalkeeping coach messaged me wanting to chat.

There’s a feeling that the new generation of football club analysts and coaches, routinely more formally educated than their predecessors, are embracing new ways of communicating their ideas about the game. Maths Elfvendal is definitely one of these guys.

“Wherever you’re working you need to be good in a lot of areas to be a good coach these days," says Elfvendal, “but especially the bigger the club or the bigger the national side. It’s getting complex. You need to handle the social relationships. With the national team you have one, two, three goalkeepers who think they should be playing. You need to handle them with care – both individually and as a group.”

Elfvendal has been a semi-professional footballer in Sweden. His father was goalkeeping coach for the Swedish U21 team, and coached in the Swedish top flight while Maths grew up looking on. Now the boy is grown up and goalkeeping coach for both IFK Norrköping and the national team. Elfvendal is still only 31 years old but has somehow also managed to fit in 5 and a half years of university - learning to be a secondary teacher in social studies. He sees his educational experience every bit as important as his footballing background: “I adapt myself to the goalkeeper I have. I speak to every goalkeeper in a different way. In one way I have those years learning how to teach. In another way I have years of experience in the dressing room and hear what footballers say. I need to adapt.”

The concept of adaptation comes up repeatedly in our two hour chat. Elfvendal believes the new wave of technology and information available now is changing the game rapidly. It’s a matter of keeping up and developing your own philosophy or being left behind. “I’ve been reading your blog and it’s helped me a lot to build my own philosophy, both from statistics and also experiences with goalkeeper coaches and players,” says Elfvendal casually. I nearly choke on my cup of tea. “A lot of football experience can be short-cut these days. With all the information we have you can gain the necessary experience and knowledge of the game much faster now.”

I have to admit, despite being flattered by Elfvendal’s comments I’m still a ‘football philosophy’ sceptic. If you have three keepers to look after with the national team and they’re all different how do you approach a training session they’re all involved in? “That’s interesting. They are different, definitely.” he says. “Physically, technically. They also play in different leagues. On international duty the standard is only three training sessions before a game. For me, to believe I can change them technically in that space of time and for them to then perform at their best would be naive. With the national team my training sessions are based on tactical aspects for the next game, for the next opponent. In that sense it’s easier. How do we want to build up our play, how do we need to protect the area from crosses or from cutbacks. These positional changes we can change a little bit. It’s more based on the game plan so the whole team is on the same page. At a club there’s more time to work on technical detail. Also, you have to respect that the clubs own the players, we just borrow them for the national team. I don’t want to change anything that will negatively impact them when they go back to their clubs. I don’t want to say something when the coach at their club says otherwise.”

The teacher is eager to test me using some of the presentation slides he uses when delivering lectures to other coaches. “What position do you prefer the goalkeeper to take up?” he says flicking up a still of an attacking situation. The goalkeeper has been removed from the image. “See the positions marked there? One, two, three, four, five. I want you to tell me in 5 seconds what position you want the goalkeeper in.”

“One or two?” My answer is more of a question.

“Yes, thanks, next!” barks Elfvendal. “One, two, three, four, five?”


We go through a couple more before this bomb is dropped on me:

I take longer than 5 seconds. “Er, five? I feel worried now, Maths.” He laughs at me.

I start bleating: “It depends on your goalkeeper and what you want the team to do I guess.”

“Ah,” he says switching to the next slide. “It’s in Swedish there but it says ‘What information do you need to have to answer the question of what the best position is?’.”

“Are you asking me?”

“Yeah, you taught me one of them so…”

This statement doesn’t help. I start rambling about what your coaching style is (are you leading as coach or are you allowing the player to lead you). Is the keeper good at moving? Can he move his feet?

“Ok, that’s two. Team tactics and goalkeeper style. Four more.”


"You don’t need to answer, it’s just a fun game.” He sounds disappointed. I try and up my game.

“Ok, so I want to know where my defenders are. Do I want to be aggressive and hit the opposition on the break if I can quickly gather it?”

“That’s still tactics. I don’t have all the answers here…” My brain has gone.

“Tell me what else?”

“Expected goals! What is the expected goal value of a shot from here?”

“Next to nothing."

“Right so what is the expected goal value if he is assisting one of the forwards? He can cross it here. There’s a defensive line four versus two. As a keeper you can either be aggressive and come and get it, say at position 2 or position 4 on the picture.”

I remark that the Premier League I see more and more that keepers are taking up position 7 or even a 9 as if they’re terrified of being beaten on the near post.

“Yeah, you have a big problem there if the header comes.” Elfvendal modifies the picture an adds an extra attacker: “How does your position change now?”

“Possibly between 5 and 7?”

“This is really interesting”, he says. “Do you think if the ball is played into him where the attacker has moved to now, do you have enough reaction time standing on his line?”


“Yep. So if the ball is played in front of him to five and a half metres…ah…to the six yard line, I am talking to an Englishman now. Do you think you have reaction time?”

Elfvendal is well aware of my comfort zone preferences. He’s fishing. Images of David De Gea saves flash through my mind. I take the bait: “Yes.”

“I think you overestimate a little bit,” he laughs. “From my point of view you will have difficulty reacting in a good way from there. A guy called Scott Peterson is doing some science about this. What’s the likelihood of saving the ball depending on the distance between the ball and the goalkeeper? Imagine you are in position 8. You will be one to two metres away from the striker, less reaction time but close enough to block the sight of the whole goal with your body. Back on your line you have more time and reach but are not covering so much goal. Also Scott’s research shows that the conversion rate for a goal when the distance between ball and goalkeeper is 2-7m is significantly higher than any other distance.”

I start protesting about sample size, the possibilities and permutations of what could happen as things stand in the still image. Anything could happen from here. Is Elfvendal teaching physical cues? He flicks another image on screen. “I showed this to one of the participants on my course,” he says.

Yeah, by the way, Elfvendal is a course instructor on the UEFA goalkeeping A License. “We’re just looking at the biggest threat,” says the Swede. “From my point of view I’m trying to prevent a high value xG chance here. From position 2 or position 4 I can gather a cross to stop the header every time. I can also move to position 8 quickly if there is a striker coming to the near post like the second picture.” He shows me several video clips of keepers doing just that. Then he shows me another still. Pretty much the same as the first two but the man with the ball is just wider, out near the touchline about 25 yards out.

“What if the keeper is super aggressive? What if he is out like near the penalty spot leaving his goal open? How does the xG change?”

I’m still in stupid mode: “There isn’t enough sample to model it.”

“I was expecting a deeper answer here,” he says sounding disappointed again. He perks up immediately and laughs. “Use your imagination! You can be aggressive here. I showed the goalkeepers, I put them in the position on the ball near the touchline that far out. I stood myself near the penalty spot. Try and score against me guys. Left foot from there, score on me now. They didn’t score a goal I can tell you that. It’s harder than people think. By being higher, you are not risking too much being beaten from there, but you’re helping the team by protecting a higher xG value chance being made from the cross.”

And it dawns on me that right here is the value of theory meeting a real life practitioner. A practitioner influencing real outcomes, taking it to the next level with a logical step. I’ve been looking at this stuff for years, I’ve never even thought of it this way and this guy is here crediting me for the inspiration. “I see all kinds of rubbish on the internet about evidence based coaching,” I say. “This is the real deal.” “Yeah,” says Elfvendal, satisfied.

After two hours, I think the coach is finally happy with me. He’s used every trick in the teacher’s book – serious voice, disappointed voice, gentle mocking, laughter and praise to bring it out of me.

And how do I feel?

In footballers parlance: “I’m buzzing.”

Courtois and Pickford: The Tall and Short of Keeper Styles

At 19 years old, Thibaut Courtois was Diego Simeone’s first choice keeper at Atletico Madrid. After three full seasons in La Liga he was being touted as the best young goalkeeper in the world. Four seasons on, people were more likely to tout David De Gea, the man Courtois replaced at Atletico, as the best keeper in the world. Then, at the World Cup, over the span of a few games, De Gea has a nightmare, Courtois did well, won the Golden Glove, and suddenly he, and not De Gea, who’s on his way to Real Madrid. Welcome to the football merry-go-round.

In the last two seasons at Chelsea, Courtois has conceded one more goal in the Premier League than models expect for the shots on target he’s faced. In Russia, his shot-stopping was worth one full goal during his seven games and he had the most work to do out of all the keepers out there (Here’s lookin’ at you, Bobby Martinez!). In the middle of it all he even managed to get into a mini spat with tiny, little, Jordan Pickford.

Given time to pluck the ball out of the air from a long looping cross, there’s barely anyone better than gigantor, Courtois. He dominates aerially. He faced just three shots on target from the centre of his six yard box. He saved two of them. Pickford faced 11 and saved one. Pickford does not dominate his six yard box. He doesn’t dominate aerially. Size is important. Thibaut was right! Pickford responded to the comments by bigging up his own power and agility and not caring if he was the biggest. Power and agility is important. Jordan was right, too!

Last season Courtois had a real problem in dealing with shots coming from central positions in the area around the penalty spot. Pickford didn’t. Whisper it quietly, but it’s almost like keepers have different make ups and different strengths and weaknesses. Because of his size, Courtois doesn’t often need to power from his set position into full length dives. He doesn’t do it often, and when Courtois does need to get power from his set position, he frequently fails to do so. Because of his size, Courtois is far too in the habit of just collapsing down in order to get to the deck quicker. He has to do this because he takes up fairly aggressive positions which restrict his reaction time. Courtois’ size also goes against him when situations develop quickly. He reacts once the thing has happened. He keeps by numbers, and is reactive rather than proactive. He decides to close out shooters when the ball is already at their feet rather than anticipating the play early. He is s-l-o-w. Check out what I’m talking about:




Nit-picking? Maybe. But these are the small differences that make or break a goalkeeper’s season.

Courtois’ save % from this area was 50% and way below average. Pickford’s was 64%. And those shots from wide areas in the penalty box like Adnan Januzaj’s goal against this summer Pickford? Last season Pickford saved 19 out of 22 of those. Courtois saved 10 out of 17. But, given time to react from longer range shots outside the area centrally, Courtois swallowed them whole. Pickford struggled. These patterns were exactly the same for season 2016/17, even with Pickford plying his trade at a different club with a different set-up.

Football’s analysis is often confined by week to week constraints. There’s always a game around the corner during the season that needs to be prepared for. But, if you don’t break down a keepers’ numbers it’s difficult to break down their game. You could watch every game in real time and not note these patterns. The record of what actually happens, the information in the long term data highlights the problem. Long term success needs long term analysis and planning. Football has more flashes in the pan than a wok chef with pyromania. The need to ignore short term narratives is huge.

Courtois’ weaknesses also highlights another keeper coaching bugbear of mine. Look at all the publicly available coaching videos. There’s more repetition in the drills than a Jive Bunny track. The keepers know what’s coming. Footwork steps, dive, get up, speed back to start position, footwork steps dive, get up, speed back to start position. Yes, developing some muscle memory is important, but how are you teaching visual clues as to what’s going to happen during the actual match if it doesn’t match your rigid training exercise? Saving a shot involves footwork, it involves diving technique, agility, power, handling. But, first of all, it involves making dynamic decisions about how to handle each situation as it develops. Coaches are taking this away in their sessions.

Every recorded shot on target in a model has all this information built in by virtue of it simply happening in thousands and thousands of top level matches over many years. Long term data tells you what’s working and what’s not. Use it. Or don’t.

At window’s close, with Courtois off to Madrid, Chelsea spend a whopping £72 million to replace him with Kepa Arrizabalaga. Pickford, who was briefly rumored to be on Chelsea’s list to replace Courtois stayed at Everton for at least another season. Kepa is, as yet, unproven in the Premier League, but to prove himself better than Pickford he’ll have to clear a very competent bar. In the last two seasons, Pickford has saved three more goals in the Premier League than models expect for the shots on target he’s faced. Meanwhile, De Gea, sitting pretty above this summer’s transfer fray, he’s saved about five or six times that.