soccer, chance, and attribution, continued

As I argued in an earlier post, football is an inherently probabilistic game. Here I’d like to expand a bit on what I mean, and look at some (preliminary) evidence.

Clearly, everyone realizes that chance and luck play some role in soccer (indeed, in any sport). I’d like to argue that it plays a rather larger, and more specific role than we might think. In particular my hypothesis is that we can predict the distribution of goals in a soccer match and over a number of matches with a fixed-probability model. Imagine a soccer game is like a series of coin tosses of a very, very unfair coin. In each minute of a soccer match, we toss a coin that has about a 1/35 probability of landing on heads. How many times will it land on heads?

My hunch is that that the number of heads you get in this experiment is the same as the number of goals you get in any given soccer match, which (if true) means that in every minute of a soccer match there’s more or less a fixed probability that one or the other team will score.

This isn’t what we expect, or what conventional wisdom would predict. We like to think that in a 0-0 soccer game, the teams just didn’t attack very well, or defended very well, or both, and that in a 4-3 game, the opposite is true. Those teams really came out with attack-minded tactics and didn’t play defensively at all! And they did brilliantly, too! Right?

more thoughts on euro 2012 houghts on euros

I have to admit I succumbed to the hype of Euro 2012. I was excited to watch soccer every day, to watch some of the best teams and the best players on earth. But the tournament has, overall, been a disappointment. Let's admit it: too many of the games that were, on paper, decent match-ups, have been colossal bores. Starting with Germany-Portugal and continuing through to Portugal-Spain today, the games have been low-scoring (lowest since euro 96 overall), defensive-minded, and lacking general excitement. Even a game like Italy-England, which, to be fair, actually had quite a bit of attacking play and lots of chances (mostly for Italy), ended up with no goals at all. For me it's another sign that football, as a game, simply cries out for more goals. It's becoming a game of who can hold on to slim leads, rather than a game of who can attack the most and create the most chances. In all the rule changes I've suggested over the years for soccer, of course, I've never written about the most obvious, most consequential, and least likely to change in the near future: make the goals bigger. But that's for another time.

As for yesterday's semifinal, a few comments. First, Portugal did, in truth, defend brilliantly through the 90 minutes. Spain certainly were not at their best, and seemed to lack a lot of energy, but even a weak Spain team usually dominates possession and creates a lot more than they did. And people tend to look back (as I've mentioned before) when a team gets a clean sheet and claim that they defended well even if they just, in fact, got lucky, but in this case it was no meager stroke of luck. Portugal did what no team in the tournament had done thus far: they defended high up the pitch and denied Spain's defenders time to play the ball out. Teams have tried this against Barcelona, most notably Man. Utd in the 2009 champions league final, or Madrid in various Clasicos, but it usually doesn't work because if you apply high pressure to such a skilled team, you're vulnerable to quick attacks when the team breaks that pressure. But Spain were unable to do that, lacking, most notably, someone quick to run at defenders through midfield. They don't have a Messi, and until late in the game, they didn't even have a Pedro. Iniesta can usually take up this role, but he was unusually subdued.

An offside conundrum

If you've read anything I've written about soccer before, you probably already know that perhaps nothing annoys me more than when a team is falsely penalized for offside. So in a surprising turn of events, I'll be writing today about a new problem: the offside rule as currently interpreted allows for certain plays that should be sanctioned for offside. As you might, expect, two recent examples from Euro 2012 motivate this post: Bendtner's first goal for Denmark against Portgual, and Jesus Navas' goal for Spain against Croatia. The offside rule should be clarified so that these types of goals don't count.

The "Laws of the Game" state that a player is guilty of an offside violation if two conditions are met: 1) He is in an offside position when the ball is last touched by a player on his team, and, 2 "He is involved in active play by [either] interfering with play, interfering with an opponent, or gaining an advantage by being in that position."

Now back to the two goals I linked above. In the first, Bendtner is in an offside position when the ball is initially crossed to Krohn-Deli. He is clearly not in an offside position when Krohn-Deli heads the ball back across to him. On the initial cross, he is neither interfering with play, nor interfering with an opponent. But surely he gains an advantage by being in an offside position at that moment. If he weren't in an offside position, he would be closer to both Pepe and Bruno Alves, who could more easily track him and mark him on the following play. Now it turns out that both Bruno Alves and Pepe are giant ball-watchers, and simply turned their heads and watched as the play unfolded, in this case. However, even if they were decent defenders, they wouldn't have been able to get back mark Bendtner and prevent the goal, precisely because Bendtner was already closer to the goal. Thus, according to the clear and obvious meaning of the words in the offside rule, Bendtner is guilty of offside.

But wait! Since the offside rule is so complicated, FIFA appends a whole section to the "Laws of the Game" clarifying its interpretation. As you can see if you care to look at page 109-110 (that's right) in this PDF, you'll see that precisely this type of play, is deemed "not an offside offence." In fact, the phrase "gaining an advantage by being in that position" is furthermore defined to encompass only two specific situations, namely being an offside position when a teammate makes an effort on goal that rebounds off the goalpost or the goalkeeper.

That's it! Of course, FIFA can define the rules as it wants. But is it really "fair" in some more objective sense to allow these types of plays to proceed and not be offside? Well, by now you probably know what my answer is! To help you see why I think so, take the situation to its logical extreme. Imagine that one striker on an attacking team is camped out in the opposing team's penalty area (cherry-picking, as we say). Surely, the other team doesn't have to mind him when the ball is in the other half, since he's so far offside! That's the whole point of the offside rule, to essentially eliminate that player from relevance! But clearly, as the rule is currently interpreted, the defending team does have to mind the cherry-picker, because of the following possibility (illustrated in the awesome image below). Imagine a long, well-timed through pass is played toward the defending team's corner flag. One attacking player, who was already running toward the corner when the ball was played, chases it, and is tracked by a single defending player. But not all the defending players were running back when the ball was played because they weren't similarly tracking penetrating runs. But what would normally be a defensive situation totally under control, as the player running toward the ball is under pressure even if he gets to the ball first, is now a very worrying situation, because the attacking player can make a simple pass across to his teammate who is now waiting, onside, inside the penalty area, without a defender anywhere in sight! This is analogous to the goals linked above; according to the rules, the play is not offside, but clearly, it should be, because the cherry-picking player in fact compels the defending team to defend him, in a manner completely contrary to the spirit of the offside rule (and, indeed, to the most reasonable interpretation of the language of the rule).

what's the point of the goal-line referee? re: ukraine-england

More thoughts to come as an overall reaction to the conclusion of the group stage of Euro 2012. But for now, the question that should be on everyone's mind (who just watched the final matches in group D): how did the goal-line referee miss that ball going over the line? I'd use this example as more support for my idea that the goal-line referee is essentially a giant misuse of precious refereeing resources. If there are extra referees in a football match, they should help call offsides, since these calls are missed much more often and, though less tangibly so, have a much bigger impact on the final outcome of matches. In addition, as we see here, even having a goal-line referee doesn't guarantee that goal-line calls will even be made correctly! Several talking points here.

First off, the obvious: England fans will be quick to point out that the play should have been ruled offside much earlier on. So maybe it's not such an unjust outcome that it wasn't ruled a goal. Fine. That doesn't interest me so much right now.

More interestingly, I wonder about two things: 1) the positioning of the goal-line referee, (is he really standing in the best position to judge whether the ball has crossed the line? NO) and 2) the training or instructions given to the goal-line referee (was he trained to stand where he was standing? Lamentably, probably. Was he directed as to how certain he should be that a goal has been scored in making the call for a goal? Probably not?)

For the first point. You'll notice if you watch this video or any other that shows the play in question (the link will probably be removed for copyright by now), that the goal line referee is standing right on the goal line, with his line of sight along it. Now some basic trigonometry should enough to convince you that, since the goalpost has finite thickness, standing here will not allow the referee to clearly see the entirety of the ball crossing the line even if it has, because his view of the ball is partially obstructed by the goalpost. In addition, because in order for a goal to be scored the ball has to cross the goal post from his line of sight, there will necessarily be a discontinuity in his view of the ball. Now he sees it, now he doesn't, as it crosses the goal line. This means, even when the ball goes in the goal, it's harder to follow from this view.

So where's a better place to stand? Closer to the fucking goal, and slightly behind the goal line, to have a better view of the ball. Standing right next to goalpost, slightly behind it, would allow the referee to rely on depth perception, instead of merely using line of sight, to see when the ball has crossed the line. This strikes me as a much better system.

As for the second point, how certain should the goal line ref be that a goal has been scored? Certainly 100% is too high a burden. I'd assume that if he was given any instruction by FIFA, it would be of the "beyond a reasonable doubt" variety, but more likely he was left to decide for himself. But of course, any close call, especially one that happens on the goal line so quickly, comes with a large degree of uncertainty. The best criterion to use in this case is a 50/50 judgment. As long as the goal line referee, who by assumption, is the best positioned to make the call, believes there is above a 50% chance that a goal has been scored, he should call a goal. My hunch is that the referee in this case maybe thought it was a goal, but wasn't sure, so refrained from calling it. What a shame! Would've made for a fine finish.

the tournament so far, quick reaction

After having seen 6/8 initial games (missed Croatia-Ireland and England-France, some initial thoughts and predictions:

1. Favorites: Spain are still my favorites to win it, but only marginally, well below 50% probability. My next pick would be (perhaps surprisingly) the Netherlands (you heard it here first!), who, after being the butchers of WC 2010 came out to play this time around. If they can build some confidence and get out of the group of death after the initial defeat, they will be formidable opponents. Technically they looked quite good and created a lot of clear opportunities. Sneijder played a really impressive game in particular. I hope van Persie can find his form again after a woeful start. Though it's just as likely he and his team will do what the great Dutch teams of the past have always done best: play beautiful soccer and choke under pressure. It will be key for them to come out in the next game and not believe what everyone said about their first game, that they played poorly and need to reinvent themselves. If they play the same way, they'll have a great chance of beating Germany and Portugal and winning the group.

 For Spain, well, they can continue to play with 6 midfielders and could even win the tournament that way with odd goals from Silva, Iniesta and Fabregas, but more likely they'll need Torres or Llorente to score at some point. Especially with Pique and Ramos not looking particularly comfortable with each other at the back (never having played together as a central defense pairing), they'll need more than the 1 goal a game that basically won them the World Cup. Not sure if that's gonna happen. On the other hand, Iniesta really stepped up as Spain's most dangerous player...if he keeps playing like that, he could be the player of the tournament and they won't need a striker.

2. Pleasant surprises: Italy held their own against Spain and are my other pick to advance from Group C. Ukraine were also impressive in midfield and attack (though perhaps not so much in defense, as they were quite lucky to escape with the victory in the end). But in a competitive tournament, home support can make all the difference. Russia also looked formidable in their first game, but the Czechs were awfully poor in defense, so I'll be watching their match closely tomorrow.

3. Disappointments: Portugal and Germany both looked lackluster. The Germans could well pull it together, but their midfield play was surprisingly vertical. Muller stuck to the right flank, Podolski to the left, leaving Oezil to be the only real creative force for them. They'll need more, particularly from Muller, to reclaim the exciting form they showed at the World Cup. I don't see the Portuguese advancing, and it'll be another disappointment for Ronaldo in a major tournament.

netherlands-denmark

The Netherlands were upset today by Denmark, despite playing well and creating some great chances. Full credit to Denmark, who took their opportunity, defended well and kept the ball when they needed to, threatening on attack throughout the second half as well. Sometimes you play well and still lose. That's football, right?

It always hurts me a little bit to see a team play well and lose, but what was really frustrating this afternoon was the inane but predictable commentary. Throughout the second half, they couldn't stop saying how poorly the Dutch were playing, how they were so uncreative and couldn't create any chances to score. Which was, simply speaking, false. This is a common mistake that people make watching soccer: they always align their opinions about how well the teams are playing with the scoreline. But the thing about soccer is, those two different aspects of a game can diverge pretty dramatically. In this case, if van Persie had brought his shooting boots, Robben or Huntelaar had converted their chances, the commentators would have been singing Dutch praises, talking about how their tactics were brilliant and how they really had the will to win. If someone had watched the game with the 30 second sequence that included the Danish goal cut out, they would have predicted that the Dutch were the ones that had scored, not the reverse.

In the end, soccer is a game not just of two teams and their quality of play on a given day, but of individual players, individual moments, and chance. People will try to construct ad hoc narratives to fit the results of matches, especially in short tournaments where every result is crucial, but these shallow analyses are an annoying disservice to the teams and players involved.

Euro 2012: it begins

Now that the dust has finally settled over the tragedy of the Champions league semifinal (and final), it's on the Euros and a chance at redemption (for the game of soccer, that is). A few things to note as the tournament gets rolling:

1. The European Championship is probably the best tournament there is, in terms of the actual football being played, given the concentration of high-level games over the course of a single month. Sorry FIFA, but the Euros offer higher quality play, with fewer teams, and all of them just incredibly good. The World Cup is great for spectacle, but the North American, African and Asian confederations still lag behind Europe and South America and dilute the overall quality of play. (The very best matches are at the club level, but are distributed sparsely throughout the season, only when the very best clubs play each other.)

2. The past four years have been the era of Spanish-style attacking football, with Spain winning the last two international tournaments and Barcelona dominating (to a greater or lesser extent) the club level in Europe. After Guardiola's recent retirement, people in the football world have been talking about how he has changed the game for the better by making the attacking, passing, free-flowing style a staple. Though he deserves enormous credit, Barcelona and Spain were already in ascendance before he took over.

One thing that has contributed enormously—but invisibly, given that no one ever talks about it—to this ascendance is the improvement in the enforcement of offsides over the past decade. People say that soccer needs video review technology. Well, video review has already made an extreme difference, just not in the way people thought it would. Several years ago I watched the 1974 World Cup final, a classic match between Germany and the Netherlands. I was shocked to find that, in those days, players were called offside on plays that, today, most people would recognize as clearly onside. But nobody could rewind the tape in those days and see what was really going on: defending players stepping up after a ball was passed to an attacker, thereby making the play look offside when in fact it wasn't. I was lucky enough to see, in the age of the emerging DVR, how often assistant referees wrongly called offsides because of the the time it took to shift their attention from the source of the pass to the player in question, combined with the flash-lag effect.

The improvement in offside calls (or, mostly, non-calls), while vastly underestimated by players and commentators alike, makes good timing and fast attacking play a much more rewarding tactical option. In possibly the greatest soccer performance of all time, Barcelona's 2010 5-0 massacre of Madrid, 3 of Barcelona's goals were barely onside. Ten or even five years ago, all or at least a couple of them would have been called back before the players even had a chance to finish, and the game would have been much different.

In both of today's matches, crucial non-offside calls played a critical role, not in the results themselves, but in the play of the match overall. In Poland-Greece, the pass that led to Greece's penalty and Scezny's sending off was a very close call, as was the Czech Republic's goal against Russia. These aren't just isolated incidents. They happen game after game after game, and they are slowly having less of a negative impact on the game.

Game on!