Third and final post on Jared Young’s awesome analysis of MLS goal kicks on americansocceranalysis.com.

In our last posting we looked at how he show that long balls (i.e. goal kicks that went into the opposing half) statistically increase the opposing team’s goalscoring chances, while decreasing those of the goalkeepers team.

So now let’s look a short balls (i.e. balls received within the keeper’s 40% of field). The first possession of the offensive team results in a goal just 0.9% of the time. This is understandable given the team is beginning their possession further away from goal. If the defense gets the first possession they have an average chance of scoring of 1.2%. So far, advantage long ball.

But again it’s on the second possession where things get interesting. The offensive team scores 1.4% of the time and the opposition’s second possession results in a goal just 1.0% of the time. The results have flipped compared to the longer pass. Factoring in the percentage of first pass completion, then a shorter pass from the goalkeeper results in a goal 2.3% of the time over the next two possessions.

So if an average team decided to only have the keeper make passes within their own half and these results held, the team would improve their goal differential by 1.6 goals per season. That’s not a lot of goals – but in a tight season it could be the difference between top ten and top five in the table.

Jared’s hypothesis for why this shift occurs is due to the positioning of the opponent. In other words, the long pass allows the defense to get set deeper and shifts the possession odds in their favor. Meanwhile a shorter pass draws the defense forward and over the course of the two possessions increases the team’s chance of scoring – and let’s not forget nearly tripling the chances of winning the first possession. Here’s a quick chart that re-caps Jared’s long vs short ball analysis:

 

One of the things we set out to measure with Stopper was the success rate of goal kicks by the keeper. Even before we had the opportunity to read Jared’s excellent analysis, we decided to measure goal kick success as generating a second possession – which we now know leads to increased goal scoring opportunities.