Which Team has the Best Defensive Efficiency (DEFF)

28 Feb

Aim

In the last post I introduced the concept of giving a true measure of a team’s Defensive Efficiency (DEFF). For full details of the 6 metrics click here for the last post.

The aim of this post is to rank teams by their DEFF.  This will be done by looking at the number of goals a team concedes (GC), the number of goals a team concedes  from total number of shots they concede (GCTS%) and the number of goals a team concedes from the total amount of shots on target they concede (GCSoT%).

Data Collection

All data has been collected and verified from @StatsZone app and verified against the @Squawka_Sports website both of which are powered by Opta.

A shot on target is defined as a shot that has either been saved by a goalkeeper or resulted in a goal including penalties and free kicks.  A shot off target is defined as one that was blocked, hit the wood work or missed the target including penalties and free kicks.

Results

Goals Conceded

When looking at the GC the table generally follows the same pattern as that of the current standings of the EPL with the4 most efficient defences in terms of goals conceded being in the top 5 of the league with Stoke being an anomaly (5th vs. 10th in the league), providing some more objectivity to Stokes reputation of being hard to beat and not giving much away.  A similar pattern can be seen at the bottom of the table with 3 out of the bottom 4 teams (Wigan 51, Aston Villa 50 and Reading 48 GC) with the most GC being in the bottom 4 of the league.  The biggest surprises in the GC Table are QPR who lie 13th (41 GC) as opposed to 20th in the league, and Manchester United who lie 6th (31 GC) in the GC Table which indicates both how poor QPR’s attacking players are (19 goals scored) and how good United’s forwards are (62 goals scored).

Goals Conceded From Total Shots (GCTS%)

This is where the Table starts to become interesting and indicates a team’s true DEFF.  From there being a total goal difference of 19 goals from Manchester city (24GC) to Wigan (51GC) when converting to GCTS% there is only a 5% difference in efficiency from top to bottom clubs.  The first thing to note is the change in make up the top 4 teams; Sunderland, Swansea, WBA and Stoke, who only concede 8% of the total number of shots. What’s interesting is that these 3 teams also concede some of the highest number of shots yet concede very few.  Sunderland in particular show that while they have TSC of 443 they limit teams to low quality chances a good sign of DEFF.

The teams with the highest GCTS% again see’s Wigan as the worst club (13%), however Tottenham have dropped from 4th in GC to joint bottom with a GCTS% of 13% from 248 TSC which is actually the least number of shots conceded in the league.  This indicates that either Lloris isn’t particularly safe or the chances the team are conceding in highly susceptible to conceding shots in high % goal scoring areas such as the famed double 6yrd box. 

Table

Goals Conceded from Shots on Target (GCST%)

Once again there is quite a change at the top of the table with Chelsea and Swansea conceding the least (24%), Wigan are rock bottom again (38%). Swansea prove an interesting case conceding with one of the highest SoTC rates yet joint 2nd in GCST% indicating that they may be both lucky and that Vorn is an exceptional goalkeeper.   Suddenly there is bit more context to the DEFF of Manchester City.  Previously coming out top in GC and GCTS% they now lie 14th conceding 33% out of 77 SoT which for a team in 2nd place is an abysmal DEFF.  This indicates that while they may not concede many shots the quality of the chances are either very high or Joe Harte isn’t quite as good as we possibly think?

The other major eyebrow raises are Tottenham (34% out of 89 SoT), Liverpool (36% out of 95 SoT) and Everton (32% out of 99 SoT) all showing that while these three teams may be a bit more gun hoe in their attacking play they are extremely susceptible to conceding goals.   Interesting QPR come 9th (30% out of 138 SoT) reaffirming the previous statement on their inability to score as oppose to conceding goals being the reason for their league position.

Conclusion

Based on this initial analysis it would appear that GC may not tell the whole story of DEFF with GCTS% and SoTC% being a truer measure.  What is clear is that Wigan has by far the worst defence in the league and that QPR were right to invest so heavily in Remy to try and chase those elusive goals. Tottenham may have been a bit hasty in replacing Freidle as first choice keeper and that Liverpool are ‘work in progress’.

Moving forward I will look at the relationship between goals concede and TSC to determine just how much a causal effect conceding shots are on conceding goals.

One Response to “Which Team has the Best Defensive Efficiency (DEFF)”

  1. differentgame March 3, 2013 at 11:18 am #

    City concede less than the avg from the shots they face inside the box. Hart has shown a weakness from open play SOTs outside the box. He’s also let in more free kicks than the avg.He hasn’t conceded at all from wide areas inside the box

    Spurs have conceded nearly all their goals from central inside the box. Both Friedel and Lloris have been involved in this. They barely concede from wide inside. More likely that the defence is more the issue. They change round a lot there through necessity or oppo.

    Spurs concede way more than avg from these areas – at Wigan levels. On top of that Wigan have conceded 6 pens which may skew it even more if you are counting these?

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