Bayern Munich: Shot efficiency as an indicator for goals and scoring this season

This season we've seen Bayern Munich launch with a subtlety new style of play that has led some to thoughts that Bayern Munich has been inefficient in attack and in front of goal.

Of course, we are comparing it to our memories of a Jupp Heynckes squad that was tactically dominant on both ends of the pitch. Our perspective is colored by our impressions and emotions of the highs (there really weren't any lows) of last season's treble winning performance. Fortunately for us, statistics are immune to the vagaries of emotion and present us with a more realistic picture.

With that being the aim, let's look at shooting efficiency between the two sides. A decent metric would be to use shots on target/totals shots yet this doesn't give us with a complete picture of how these matches played out. Many times, teams have had impressively dominating games only to by stymied by a conversely incredible goalkeeping performance from their opponent. In a similar fashion, teams can hammer a bunkered opponent with overwhelming force and an incredible number of shots, only to end the match with a draw as countless bodies are thrown in the way of those shots. To that end, a new metric for assessing shot efficiency is needed:

Shot Efficiency = (Shots on Target - Saves) / (Total Shots - Blocked Shots)

The aim of this metric is to evaluate quality shots on target per actual shots. The majority of saves made by goalkeepers are not tips over the bar or diving full stretch fingertip saves; those highlight reel saves. Most saves are ordinary shots directly at the keeper. The same criteria goes for blocked shots as the vast majority of these are bounced either out of play or back into midfield for the opposition to recycle their attack.

Using the developed metric against goals scored gives us an equation for shot efficiency in relation to goals scored:

Goals = 6.7826 (Shot Efficiency) + .3878

The metric itself has a correlation of over .5 and does a decent job of relating quality shots to goals scored. (For comparison, shots on target correlates at .28 while total shots correlates at .08; both poorly suited to comparison to goals scored). We're using a linear fit, because as the quality shot to total shots ratio increases, goals should also increase. There is no condition upon which it could decrease.

In assessing Bayern's shooting efficiency this season , we'll first look at the goals the average 2012/2013 Bundesliga side and the average 2012/2013 Bayern Munich side would have scored with Bayern's shooting efficiency this season (predicted goals for 2012/2013 Bayern Munich use a Bayern specific version of the above formula). Then, we'll look at how many extra goals they've produced in each match this season.

Table 1. Goals scored by average 2012/2013 Bundesliga side and average 2012/2013 Bayern Munich squad in all 2013/2014 Bayern Munich competitive matches

Table 2. Goals scored above the projected amount for the average 2012/2013 Bundesliga side and average 2012/2013 Bayern Munich squad in all 2013/2014 Bayern Munich competitive matches

While the UEFA Super Cup against Chelsea (as well as the Moscow UCL match) suffers from the caveat that we are performing Bundesliga specific analysis on a non-Bundesliga match, it's still very telling that Bayern outperformed their expectation by over a half a goal against a Chelsea-masquerading-as-a-theoretical-Bundesliga side.

In reality this year's Bayern Munich squad has been more efficient in front of goal than the average Bundesliga side from last season, and they've actually been more efficient than Heynckes' Bayern was in their matches. Notable exceptions being those very terse affairs in Freiburg and in Frankfurt.