Friday, March 25, 2011

He Shoots, (He Shoots Accurately), He Scores: Goals and Shots in the Premier League This Season

I thought I'd provide a quick and ready update on offensive production metrics this season in the EPL. Here are the overall averages per team/match, ordered from highest to lowest scoring teams, as of late February, 2011.

You can see that Man U and Arsenal lead the pack in producing goals (and Chelsea and Man City not too far behind); Birmingham brings up the rear, along with Wigan, Wolves, Fulham, and West Ham. But you can also see that there is lots of variation across clubs in the average number of total and accurate shots taken. Chelsea and Arsenal lead the league in overall shots as well as numbers of accurate shots. Birmingham comes in last on both counts, while Wigan, Fulham, and West Ham perform much better on these dimensions. In terms of overall shots, Man U shoots as often and as accurately as Tottenham, Everton, and West Brom (give or take).

So how do they end up on top?

Good question. Maybe it's superior defense, and maybe these graphs help explain it (I'll leave defense for another day).

United clearly are doing something right: they are the most efficient team in the league, getting more goals out of their shots than anyone else, and considerably more than their closest competitors. So does this have to do with accuracy or conversion rates? Let's take a look at accuracy first (shots on target to overall shots taken).

Not obviously; Arsenal, Man City, Everton, and Tottenham all outdo Man United, but all of these teams are clearly better than, say, Chelsea (maybe this is why they wanted Torres), or lowly Stoke which is considerably worse on this dimension.

What about conversion (goals per accurate shots)? Here you go.

Clearly, the Red Devils aren't the best team in the league on this dimension, but their solid shooting statistics (shown above in the very first graph and on accuracy) combined with outperforming Chelsea, Arsenal, Man City, and Tottenham may combine to produce good outcomes. Short of a more sophisticated multivariate analysis of these data, this is just idle speculation; what the numbers do show is that Man U is not off the charts, but they consistently perform on a very high level on different dimensions of offensive production. And that seems to be the name of the game this year: consistency. Not exciting, but good enough to lead and perhaps win the best league in the world.