Team Defensive Correlations: Opposition shots vs defensive actions

This is kind of a follow-up to the article a week or so ago based on individual players, which is here.

This time, I wanted to look at how making more defensive actions correlated with conceding fewer shots on a team level. I looked at the season averages of teams from  5 years of the Premier League (2015-16 to 2011-12).

Below is are the correlations for the raw stats (ie not adjusted in any way)

Tackles Attempted Tackles Interceptions Clearances Tackles+ Interceptions
-0.306161 -0.263952 -0.01829 0.400158 -0.16018

Like for the individual stats, tackles correlates in a weak but noticeable way, interceptions barely at all, and making more clearances actually indicates that you’ve probably conceded more shots (not fewer).

Below are possession adjusted:

Tackles Attempted tackles Interceptions Clearances Tackles+ Interceptions
-0.68295 -0.67345 -0.3408 0.058162 -0.5867

Here things diverge a bit from the individual centre-backs. There, possession adjusted tackles+interceptions had the strongest correlation, but here the weakness of the relationship for interceptions drags it down.

I’m guessing that it’s for a similar reason I ventured in the article for centre-back correlations: interceptions are (my assumption is) generally more of a stylistic or tactical option than tackles are.

Still, it’s interesting that possession adjusted tackles correlate so strongly, I think. Does this mean that teams should aim to tackle more if they want to concede fewer chances? I don’t think so, I think this is one of these correlations where there is no cause. Teams that are better and who concede fewer shots also do things which enable them to tackle more, is my hypothesis.

It brings to mind teams like Bayern Munich and Barcelona, who I think are helped a lot defensively by the fact that they are so threatening offensively. From my observation (and this is all I’m basing it on), teams tend to attack against these teams with fewer players, wanting to keep more men back to defend, and this makes it easier for the dominant team to pick off these isolated forwards.

I thought I’d check how La Liga lined up too, as probably the big league with the most different style to the Premier League, and was immediately hit by a problem. These are the correlations for 5 seasons of shots conceded vs 5 seasons of possession adjusted stats in La Liga.

Tackles Attempted tackles Interceptions Clearances Tackles+ Interceptions
-0.35899 -0.42318 0.126732 0.225672 -0.03452

Check these against the table for the Premier League. They’re a lot different. However, in trying to make sense of this I mocked up a scattergraph.

LALIGA CORRELATIONS

It turns out that the little band of dots hovering above everyone else in the top right hand corner are basically the class of 2011-12. For some reason that season’s stats were consistently different, and you can see it. It seems like it’s the interceptions that’s the problem; the 2011-12 average for raw interceptions per90 in La Liga is 30.39, for the other four seasons the combined average is 17.25. Why this difference is present, I dunno.

Once you take out 2011-12 from the La Liga sample though, these are the correlations you get (and I’ve included the Premier League’s to save you having to scroll up again)

League Tackles Attempted tackles Interceptions Clearances Tackles+ Interceptions
La Liga -0.4786 -0.46382 -0.27229 0.440434 -0.47374
Premier League -0.68295 -0.67345 -0.3408 0.058162 -0.5867

The correlations aren’t quite at the level of strength of the Premier League, but they’re a lot closer, and the general patterns are a lot more similar too.

I don’t have any theories about the differences. I know that measures like shot ratios and expected goals differ from league to league, and I don’t know if anyone’s been able to decide why that happens either.

So there ya go.

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One thought on “Team Defensive Correlations: Opposition shots vs defensive actions

  1. Pingback: Our lexicon for defending in football isn’t good enough | Every Team Needs A Ron

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