Sabermetrics applying to Soccer

[kenntomasch]

Matt Bernhardt from Ohio State did a plus-minus analysis of the Crew one year.

All I remember is that it tended to indicate that the Crew was better off with Brian McBride off the pitch than on the pitch.

A little common sense doesn't hurt sometimes. :)

[skipshady]

So I see that plus/minus wouldn't be that meaningful for soccer, at least copied directly from hockey. But how about plus/minus for players by positions? For example, can we measure the effectiveness of Claudio Reyna when he is used at the top of a diamond compared to in a box or in a flat four midfield? Or the team's effectiveness when Reyna is a) in the 18 yard box, b) between the center line and the box, c) in the right third of the attacking third, etc etc.

Of course, a team's formation depends greatly on the whether it's ahead or behind and the other 10 players on the field, and different players switch positioins at different frequencies. Obviously, the stats would not so useful on their own. But again, I'm just throwing out an idea.

[kenntomasch]

We can count anything you want. If you have access to the games and can keep track of what you want.

[mpruitt]

Assuming there are some people trully excited about this, and that we could form an Association of Soccer Nerds, then maybe we need some organization or discussion as to what to start begin to look at, or how to look at it. Furthermore, I think the whole point of any of this should be to be willing to question everything you think you know about soccer. A poster before said that he didn't think this stuff woudl be as usefull because there are too many events which lead up to each individual goal. Well, maybe that's true. But how do you know that? I'd like to try to assume that as many things as possiable in soccer idealy could be quantified objectively.

[joe2]

The problem with trying to quantify events in soccer is extremely great. What events lead to a goal ? the last pass ? The three previous passes ? The misplayed ball at midfield that lead to a 4 pass combination in which an unmarked defender was able to slip through the defense and score a goal on a ball that richoted off an outstretched leg of a defender ? The fluidity of the game defies quantification. It is easy to make up statistics after the fact by collecting whatever data you want. But what data is meaningful ? I contend that none of it is meaningful unless it is predictive of future events. Unlike American football and baseball with plenty of set plays and stoppages soccer is a continuous action sport. Players are constantly adjusting to the changes in the game. An attacker might find himself defending in his own box and a defender might find himself able to score. The few discreet events that are quantifiable: goals, shots, corner kicks, fouls, assists, saves, cards given...really do little to express what the game is abou or even the quality of play. I would like to see someone come up with a list of discrete quantifiable actions that are meaningful in evaluating performance while being able to be easily collected and agreed upon by unbiased observors. Unless you can do that you are just assuming certain events are more important than others. In the end the only important events in soccer are goals. And such events as gamewinning goals are especially meaningless. Any goal could be a game winning goal depending on how many goals a team gives up.

[microbrew]

Most of the literature I've read is dealing with game theory and soccer, i.e. decision making in games (strategy and tactics) and the running of leagues. So, I guess I would be more of a armchair coach, than an armchair GM.

More articles:

"Skill, Strategy, and Passion: an Empirical Analysis of Soccer" at
http://ideas.repec.org/p/ecm/wc2000/1822.html

This is the one I'm trying to chew through right now- damn you guys. I haven't touched this stuff in four years, and now I can't resist trying to make sense of it.


"A simulation model for football championships" at
http://www.ub.rug.nl/eldoc/som/a/01A65/01a65.pdf

I've only read the abstract so far, but it claims: "[...] a simulation/probability model that identifies the team that is most likely to win a tournament. The model can also be used to answer other questions like ‘which team had a lucky draw?’
[...]"
The keywords: Poisson models, football, simulation

So maybe beineke was onto something.

[nancyb]

I thought this was about some Star Wars-based game.

[Real Ray]

Originally posted by joe2
The problem with trying to quantify events in soccer is extremely great. What events lead to a goal ? the last pass ? The three previous passes ? The misplayed ball at midfield that lead to a 4 pass combination in which an unmarked defender was able to slip through the defense and score a goal on a ball that richoted off an outstretched leg of a defender ? The fluidity of the game defies quantification. It is easy to make up statistics after the fact by collecting whatever data you want. But what data is meaningful ? I contend that none of it is meaningful unless it is predictive of future events.

I'm not sure I really agree with this.

For starters, the basic "stat" that I think we could all come to agreement on is what we all refer to as a "chance." Breaking down tape and then processing the data to show a correlation between the number of chances vis-a-vis specific players on the pitch, ect., is a basic tool already. In fact, before the BS crash, there was a thread in the Coaches forum that brought up one of Dave Dir's old columns that had an an analysis of how the MetroStars did when Villegas was able to get certain numbers of crosses in. It was due to this that Zambrano-despite-Villegas' flaws as a player-played him, as he felt given those opportunites to cross, good things would happen inside the box.

I would also be interested in seeing success-faliure rate on chances based on where key players get the ball. Space is critical to soccer-you could argue it's the true currency of the sport. Creating space, closing space-sure it's a painstainking process but is has promise/worth IMO.

For instance, a trend that you see in basketball that I would love to backup with numbers in soccer, is the number touches-passes received by a player, based on the quality/success of what that player does with the ball.

In the NBA an example was Jason Kidd-Keith Van Horn w/the Nets. If you watched the games, you could see the trend very early that if Van Horn did not get off well, Kidd would pretty much freeze him out. This led to problems in the dressing room as well, and Van Horn was later traded-much to the delight of some of the Nets. I suspect if you broke down the tapes, there was a certain number points by a certain time in the game, that you could count on re: when/if Kidd would freeze him out our go with him the full 48 min.

Basketball is an easier game to track in this manner, but I think you'd find similar trends in soccer that could be exploited-why and when does that striker or midfielder all of a sudden seem to not to get any touches? Is it tough marking, his fitness-or is there a "deadline" in a match based on how he plays early in a match-do the other players freeze him out? And how does that player react? Does still work hard or does he sulk and drift away? Important stuff to know, and better to back up with hard data to show your players.

Your point about the fluidity of the game I would agree with, but I think you can breakdown soccer to create a game of percentages-which is really at the heart of baseball stats: getting your matchups right; having the percenatges on your side. Which in MLS, considering that the teams can play each other up to four times, should be easier if the teams dedicate the time and resources.

[beineke]

Originally posted by Real Ray
I would also be interested in seeing success-faliure rate on chances based on where key players get the ball. Space is critical to soccer-you could argue it's the true currency of the sport. Creating space, closing space-sure it's a painstainking process but is has promise/worth IMO.


Very interesting post.

Just to touch on this one point, I can't think of any quick and dirty way to measure space directly. However, simple play-by-play tracking provides valuable information about space. Here is one example from a stretch of the US-Portugal game that I tracked. Portugal had possession in the attacking third of the field, but they were forced to make a series of backward passes that went all the way back to their own keeper.

Even though the tracking itself says nothing directly about spacing, the implications are clear: either the US was covering space extremely well, or else Portugal's attackers weren't getting into position to make a positive play.

[joe2]

Originally posted by Real Ray
I'm not sure I really agree with this.

For starters, the basic "stat" that I think we could all come to agreement on is what we all refer to as a "chance." Breaking down tape and then processing the data to show a correlation between the number of chances vis-a-vis specific players on the pitch, ect., is a basic tool already. In fact, before the BS crash, there was a thread in the Coaches forum that brought up one of Dave Dir's old columns that had an an analysis of how the MetroStars did when Villegas was able to get certain numbers of crosses in. It was due to this that Zambrano-despite-Villegas' flaws as a player-played him, as he felt given those opportunites to cross, good things would happen inside the box.

I would also be interested in seeing success-faliure rate on chances based on where key players get the ball. Space is critical to soccer-you could argue it's the true currency of the sport. Creating space, closing space-sure it's a painstainking process but is has promise/worth IMO.

For instance, a trend that you see in basketball that I would love to backup with numbers in soccer, is the number touches-passes received by a player, based on the quality/success of what that player does with the ball.

In the NBA an example was Jason Kidd-Keith Van Horn w/the Nets. If you watched the games, you could see the trend very early that if Van Horn did not get off well, Kidd would pretty much freeze him out. This led to problems in the dressing room as well, and Van Horn was later traded-much to the delight of some of the Nets. I suspect if you broke down the tapes, there was a certain number points by a certain time in the game, that you could count on re: when/if Kidd would freeze him out our go with him the full 48 min.

Basketball is an easier game to track in this manner, but I think you'd find similar trends in soccer that could be exploited-why and when does that striker or midfielder all of a sudden seem to not to get any touches? Is it tough marking, his fitness-or is there a "deadline" in a match based on how he plays early in a match-do the other players freeze him out? And how does that player react? Does still work hard or does he sulk and drift away? Important stuff to know, and better to back up with hard data to show your players.

Your point about the fluidity of the game I would agree with, but I think you can breakdown soccer to create a game of percentages-which is really at the heart of baseball stats: getting your matchups right; having the percenatges on your side. Which in MLS, considering that the teams can play each other up to four times, should be easier if the teams dedicate the time and resources.

An interesting point but you seem to be evading my key criticism...How do you define and measure your discrete event ? For starters...What is a chance ? When does the chance start ? Is it the keeper's pass ? Or some other combination of touches ? There seems to me to be way too much margin for judgement on the part of the observor. In soccer, unlike baseball or even basketball, any given individual player is more dependent on the skills of his teammates. That is one reason you do not have players actually dominating games, as a pitcher can do in baseball, for example. Back to the idea of "chance"...define it in discrete measurable terms. Then, explain to what extent it is important. What is a "chance" and what is it's usefulness in the game ? Are you talking about any given individual's touches ? Are you talking about scoring opportunities ? Are you talking about territorial gain ? Are you talking about controlling time ? What is your operational definition of chance and why is it an important variable. Once you have done that maybe we can see if there are objective ways to quantify "chance". It could be an interesting statistic if you can define it.

[Real Ray]

A "chance" (part of the venacular, really, as in, "United need to take their chances...") is simply a play that results in or by any resonable measure, should result in an attempt on goal.

It's really one of the fundamental points of the game you here stressed in every match by players and coaches-which is why I think it serves as a basic starting point for a statistic-and one that by and large people could come to a reasonable conclusion on in the review of a match.

You look at player like Zidane and see if there is a direct correlation between the number of touches he gets and the number of chances for Real Madrid-is there a number? Is it related to where he gets the ball? To where other players play? Whether he pushes forward into the attack after his pass or hangs back? The players up top?

And I would add it's not as subjective or random as you make it out to be. In fact it's no different than looking at an NFL offense: you can eliminate touchdowns or long gains that resulted from broken plays or slips by the opposing defense, and isolate on plays that worked due to the proper read or execution. The same in soccer. You can breakdown the tapes so that you eliminate what are chances or actual goals created by fluke plays of slips, and look to see what combinations or style of play provide you with the highest probablity of success.

An interesting case I would loved to have looked at would have been David Ginola when he was at Spurs with George Graham. There is a funny story where after a match, Brian Clough noted that, "the young man from France crosses the ball beautifully." Graham replied, "but the trouble with Ginola is that he wants the ball all of the time, " which caused Clough to come back with, "well, in that case, give him the bloody thing." Perhaps Graham was right, the Ginola was a self-indulgent, flair player. But what if his bias towards these type of players was blinding him from what could be proven statistically? That Spurs actually had more chances the more touches Ginola got-that like some NFL backs, you have to give them 30+ carries to see the best results?

[beineke]

Originally posted by joe2
In soccer, unlike baseball or even basketball, any given individual player is more dependent on the skills of his teammates.

Perhaps, but the point guard only gets the assist if his teammate gets into position for the pass, catches it, and makes the shot. That's not too different from soccer. In football, if a quarterback has bad numbers, it could be his own fault, or it could be dropped passes, or poorly executed routes, or missed blocking assignments, or lousy play-calling. Even so, the stats are useful ... they just require a bit of interpretation.

[beineke]

Originally posted by Real Ray
What if his bias towards these type of players was blinding him from what could be proven statistically? That Spurs actually had more chances the more touches Ginola got-that like some NFL backs, you have to give them 30+ carries to see the best results?

This sounds like exactly the kind of question that Maxim has been talking about: is "selfishness" bad?

One possible way to approach it would be to pick a player like Justin Mapp or Eddie Lewis, and to track what happens whenever he receives the ball in the middle third of the field under loose defending. Some of the time, he'll take off on the dribble; other times, he'll make a simple pass. How many scoring chances result from either decision? How many goals? How many counterattacks for the opponent?

If you have a one-in-three chance of beating a guy on the dribble, when is it worth taking him on? As of today, we have very little basis for answering that question.

[microbrew]

It just occured to me- one of the strongest correlating factors for a team winning doesn't really apply to MLS. That is, in most leagues, money buys success. That increase the value of evaluating talenting as well as coaching.

[beineke]

Originally posted by microbrew
It just occured to me- one of the strongest correlating factors for a team winning doesn't really apply to MLS. That is, in most leagues, money buys success. That increase the value of evaluating talenting as well as coaching.

In this respect, it's fairly similar to college sports, where coaches are kings.

[joe2]

Originally posted by Real Ray
A "chance" (part of the venacular, really, as in, "United need to take their chances...") is simply a play that results in or by any resonable measure, should result in an attempt on goal.

It's really one of the fundamental points of the game you here stressed in every match by players and coaches-which is why I think it serves as a basic starting point for a statistic-and one that by and large people could come to a reasonable conclusion on in the review of a match.

You look at player like Zidane and see if there is a direct correlation between the number of touches he gets and the number of chances for Real Madrid-is there a number? Is it related to where he gets the ball? To where other players play? Whether he pushes forward into the attack after his pass or hangs back? The players up top?

And I would add it's not as subjective or random as you make it out to be. In fact it's no different than looking at an NFL offense: you can eliminate touchdowns or long gains that resulted from broken plays or slips by the opposing defense, and isolate on plays that worked due to the proper read or execution. The same in soccer. You can breakdown the tapes so that you eliminate what are chances or actual goals created by fluke plays of slips, and look to see what combinations or style of play provide you with the highest probablity of success.

An interesting case I would loved to have looked at would have been David Ginola when he was at Spurs with George Graham. There is a funny story where after a match, Brian Clough noted that, "the young man from France crosses the ball beautifully." Graham replied, "but the trouble with Ginola is that he wants the ball all of the time, " which caused Clough to come back with, "well, in that case, give him the bloody thing." Perhaps Graham was right, the Ginola was a self-indulgent, flair player. But what if his bias towards these type of players was blinding him from what could be proven statistically? That Spurs actually had more chances the more touches Ginola got-that like some NFL backs, you have to give them 30+ carries to see the best results?

Thanks for starting to clarify "chance" as a discrete event. A play that could reasonably result in an attempt on goal. This is an entirely offensive statistic, but that is okay as long as we recognize that fact. Now, when does a "chance" begin ? If a keeper makes a wonderful kick past midfield to an attacking player is that a point in his "chance" statistic ? If a midfielder makes a short pass to an attacking player and runs into space but is not given a return pass because the attacking player misplays the ball does the midfielder's run count toward his "chance" statistic ? A good pass by the attacker would have lead to a possible shot on goal. In fact, because soccer is made up a a fluid action every good pass should be considered a plus for the passer's "chance" statistic because it could reasonably lead to a situation where a player could get a shot on goal. In fact, dribbling the ball a few yards could open space leading to a "chance" if all the other players moved to space, etc. In fact, passing the ball back to a defender for the purpose of changing fields can certainly be considered a positive "chance" statistic as the passer is moving the ball to an area that could reasonably lead to a better chance for a shot on goal. In this way soccer is considerably different from Football, baseball, basketball. Let me pass the ball to Michael Jordan and I will become statistically one of the best assist men in the league. That is why statistics in all sports are fun but basically non-predictive.
You suggest that slips, and broken plays be eliminated from a statitical analysis. Why ? They are an integral part of the game. Slips often occur because a superior opponent has faked out a defender. Broken plays occur because a superior defender has busted through an offensive lineman. If a midfielder fakes out a defender and causes him to loses his balance would that not be part of your positive "chance" statistic. Actually, to fake out an opponent in just about any sport is an integral part of success, isn't it ? It is what makes plays work. Throwing a fastball when the batter is looking for a curve. Driving to the hoop then stopping for a fadeawy jumper. Faking a dive play into the line then throwing the bomb.
There is also the problem of the difference in playing styles depending on the time and score of the match. A soccer team with a 2 goal lead will often let up on the attack and play to keep the ball and use time. Statistically they are losing opportunities for good scoring chances. On the other hand, a team that is behind often increases their scoring chances by attacking. While they may look statistically superior using "chance" as a primary category, they are opening themselves up for counterattacks and playing poor defense. To use a football example: A few yaers ago the Buffalo Bills had awful defensive statistics but were a great defensive squad. But Buffalo played a hurry up offense so their defense was on the field much more than average. In fact, often better American football teams give up a lot of yards to passing. Why ? Because they have a lead and the opponent is trying to catch up by passing the ball.
I think "chance" as you are discussing it in soccer is a very hazy term and needs to be much more clearly defined to be useful. I am not saying statistical analysis is impossible but I still don't see any clearcut meaningful individual categories in soccer. Unless you develop statistics only for the entire team, maybe that would work better than trying to single out individual players for analysis. But we have that statistic already, it is called the final score !

[mpruitt]

I think "chance" would still be a little bit too subjective. One piece of data gathering that could be usefull would be to mark off the feild in an imaginary grid, mutch as the same way as you see in the matchanalysis reports, that way you could get some sort of concrete number as to when player X shoots from this space on the pitch he has a statistically better chance or has shown statistically more accurate.

[mpruitt]

Does anyone happen to know if the Michael Lewis of Moneyball is the same Michael Lews that writes on soccer for the NY Post?

[TomEaton]

For anybody who's thinking they might like to try to do some MLS statistics interpretation, just be prepared for frustration. Peter Hirdt's latest column on MLSnet asserted that there was an incredibly large correlation between--get this--goalkeeper catches/punches and winning. Yeah, I know, my first reaction to this was the same as yours: that just can't be true. But he did back up his assertions with some supporting data.

I wanted to do some independent research on this to see if the correlation really was as strong as he contended. I don't think he falsified the data; I just think he might not have been analyzing the entire issue. His company, Elias Sports Bureau (remember them?), clearly has an interest in proving the catch/punch stat to be useful.

Then I remembered that game-by-game catch/punch statistics aren't included in MLS game summaries; the only catch/punch stats available on MLSnet are season-ending and career numbers for each goalkeeper. Hirdt's contentions focused on single-game totals. So I e-mailed Hirdt, asking where I could get the numbers.

He responded but told me that the numbers aren't published anywhere. He said if I told him what kind of research I wanted performed, he'd see if he could do it for me.

See the problem? Basically, we have to take his word for it, because Elias is the only place that has access to the statistics. I was somewhat surprised he didn't offer to sell me the data, but he was probably afraid that then I'd release them publicly (which, in the absence of a contractual agreement not to, I would).

The only alternative I can see would be to go through game tapes one by one, counting up catches/punches until you had enough to do some useful comparisons. But, first, that would be an enormous amount of work, and second, THAT'S WHAT YOUR STATISTICS PEOPLE ARE FOR. The data have already been collected. By Elias. And now they won't let anybody use them. What a waste.

[mpruitt]

As I think I've said before that Bill James was quoted in Moneyball as expressing some of the exact same frustrations with Elias, that no statistics were ever given to anyone without $$$.

Going through game by game to chart whatever would be laborious at best. My insistance would be to first see if there's any other avenue in which to find more statistical information. Has anyone else been tracking this stuff, could MLS or individual teams provided it, would college teams willingly post it or give it to your average soccer fan? The college route might be one place to inquire, as any worthwhile analysis, beyond gaining a greater knowledge of the game might focus well on undiscovered players. Mabye you'd find after looking into it through statistical analysis that the NCAA isn't such a bad breeding ground for players.

I had emailed the guy from Matchanalysis and he mentioned to me that the match reports while relatively well recieved by teams haven't been as a usefull selling point as some of their video analysis. Maybe they'd be even willing to give out the stuff that they already have beyond what's on their website?