Now that the big leagues of football are finally underway, I thought it'd be fun to take a quick comparative look at last year's goal and shot ratios across teams and leagues. Recall, for starters, that the total yield (goals per shots taken) is typically very similar across the four leagues. It is usually right around around .111, as good old Charles Reep would have predicted. So in the 2009-10 season, for example, the average yields of goals per shot were as follows:
Premier League: .117
Serie A: .106
La Liga: .108
This spells 1 goal in roughly 9 shots taken. Clearly, the major leagues are very comparable on this dimension, with 2009-10 producing yield rankings that put the EPL and the Bundesliga ahead of La Liga and Serie A (in that order).
But these averages for the leagues as a whole hide a lot of very interesting variation. Across the leagues, yields vary from slightly greater than .05 (that's 1 (one!) pitiful goal in 20 shots) to Barcelona's astonishing yield of .168 (roughly 1 goal in 6 shots!). But interestingly, the variation is on a similar scale, with the less efficient teams across the leagues (Hertha BSC, Nuernberg, Portsmouth, Wigan, Lazio, Livorno, Espanol, and Valladoli, to mention a few) managing a goal ratio of only slightly greater than .05, and the successful teams (Bayern, Schalke, Man City, Chelsea, Sevilla, or Inter) producing yields around or better than .15.
As always, aside from yields, an interesting question is how well teams do at managing to hit the goal (accuracy, measured by the SOT/shots ratio) and actually scoring when hitting the goal (conversion, measured by the goals/SOT ratio). So let's take a look.