Monday, May 19, 2008

Soccer sabermetrics

If you're a soccer fan, how would you try to determine who the better players are? You could look at goals and shots, and if you watched enough games, you could get a general impression who the best players are just from watching their moves. But if you have two guys who look like middle of the road players, how can you better evaluate them?

According to
this Sports Illustrated article, private firms have been calculating additional stats for a while now: touches per 90 minutes, possessions won, passing percentage, and total distance run during a game ("top midfielders" log over 7 miles).

One of those firms is called "Match Analysis." They've been hired by Billy Beane, GM of the Oakland A's, and now "strategic overseer" of the MLS San Jose Earthquakes, to provide statistical support for what is presumably a sabermetric approach to soccer.

According to this firm, David Beckham

"... not only led MLS with an average of 87.9 touches per 90 minutes last season ... but he also dominated in shot creation – how frequently a player is involved in an attack that leads to a shot – helping to set up 11.2 shots per 90 minutes, or a whopping three more than the next-best player."

To me, these stats seem to be measuring opportunity more than effectiveness. But there's another stat, called "possession percentage" (PP):

"Ever heard of Jesse Marsch? Neither had I, but the Chivas USA midfielder led MLS in PP last year: He got the ball and passed it successfully 81% of the time. Conversely, Yura Movsisyan of the Kansas City Wizards had a 37% rate ..."
I'm not sure what PP actually measures. Is it the percentage of time you pass cleanly after getting the ball? If it is, wouldn't your percentage be lower when you're deep in the opposing zone, with more defenders in the vicinity? Anyway, I'm sure Billy Beane is busy figuring out what the stats mean and how they can be used.

In any case, I'm very optimistic about this approach, of watching and counting what happens when the player has the ball. I think it would work well for hockey, too. I remember back in the 80s and 90s, watching Leaf games, that it seemed whenever Todd Gill had the puck he'd do something bad with it ... give it away, or miss the pass. I'd bet you could learn a lot about players by just keeping track of the equivalent of "possession percentage." When a defenseman has the puck in his own zone, how often does he finish a clean pass to an open teammate? How often is the pass a bit off, where the teammate loses the puck? How often does he fail to get the puck out of the zone?

Another thing I used to notice is that Sylvain Lefebvre, my favorite player back in the early-to-mid-90s, was a rock on defense. An opposing forward would carry the puck into the zone – and Lefebvre would be on him, pinning him to the boards or taking him out of the play. Couldn't you rank defensemen by what happens when they go one-on-one with the puck carrier?

If I were an NHL general manager, I'd hire a bunch of students to watch replays of every game and tabulate all these stats. For almost nothing, you could have a record of almost anything you wanted (subject to a couple of days delay while your beleaguered interns to revisit the video). And identifying just one significantly overrated or underrated player could easily be worth millions.

Indeed, it makes so much sense that I wonder if teams are actually doing this already, and just not letting it be known.

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At Monday, May 26, 2008 6:34:00 AM, Blogger David Barry said...

I don't know much about the detailed soccer stats, since a lot of them seem to be done behind closed doors. But the English Premier League managers get their hands on all sorts of data collected by Prozone - average time spent with the ball before passing, percentage of passes forward and backward, etc.

Arsene Wenger is a huge fan (story), and apparently Beane is now hoping to get something working with Tottenham Hotspurs (story).

At Thursday, June 19, 2008 6:46:00 AM, Anonymous Anonymous said...

You might want to checkout and the book that goes into loads of detail about stats in the EPL

At Friday, September 26, 2008 4:13:00 PM, Anonymous Anonymous said...

Nice one!


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