Let’s have a quick recap on Expected Goals, or xG as the kids call it.
Not everyone is convinced of the usefulness of xG but, like every statistic, it’s all about interpretation.
The stats boffins use xG to measure a team’s actual goals against how many we would normally have expected them to score based on the quality of their chances.
Open goals from five yards out are converted into goals way more often than 35-yard bicycle kicks, and so on…
For example, if a team wins 2-0 and their xG was 1.1 while their opponents’ xG was 2.1, we can conclude that the winners were more clinical than your average team while the losers were more wasteful.
Remember back in December when Man United beat Arsenal 3-1 at the Emirates?
Aside from Jesse Lingard performing the ‘Milly Rock’, the overriding memory of that game was David De Gea’s heroics between the sticks.
And the stats back that up.
According to xG, Arsenal should have scored five goals while United showed above average chance conversion to score twice, let alone three times.
The xG metric suggests De Gea’s brilliance meant his side conceded four goals fewer than they should have in north London that afternoon.
Now, let’s apply this analysis to the entire season.
Take a look at this graphic and prepare to marvel at De Gea’s supernatural shot-stopping record…
The first column shows how many goals the xG system reckons they should have conceded this campaign and the middle column is each keeper’s actual number of goals conceded.
We can deduce then, that De Gea has saved his side between 13 and 14 goals — a huge number when you compare that to the other ‘top six’ keepers.
The impressive Ederson is in credit by just 0.41 goals, while Hugo Lloris and Thibaut Courtois have actually performed just under what you would expect.
Petr Cech has suffered a notable drop in form this season and his stats reaffirm that observation.
Even if you’re a doubter of xG, the methodology is the same for all keepers and therefore fair and unbiased.
De Gea’s significant lead can not be ignored.
Obviously, there is more to goalkeeping than shot-stopping (distribution, organisation of defence, etc) but ultimately those with the gloves are measured on how many goals they prevent.
In this sense, De Gea is over 26 times better than his direct rivals.
Best in the world? You bet…