Cech v Leno

Cech v Leno: Expected Goals Against Debate

Most Arsenal fans have cried out for a Petr Cech replacement for a number of months now. Well, the club finally listened and bought Bernd Leno from Bayer Leverkusen just the other day. On paper, it seems Arsenal has a new number one. However, the expected goals against (xGA) from last season has something to say in the Cech v Leno debate.

All stats from Understat.com

Cech v Leno: the xGA Will Surprise You

Petr Cech

Our Czech shot-stopper faced 365 shots in the Premier League last season, starting all but four matches and playing the full 90 on 33 occasions. Out of those 365 attempts, Cech allowed 48 goals. While this is not so inspiring, it is meant to be taken with the xGA, which totalled 45.33.

So, in other words, Petr Cech allowed about two-and-a-half more goals than expected in the league last season. This may not seem so impressive, however it is very normal for a ‘keeper to allow more goals than expected. After all, the majority of shots taken by footballers have a relatively small xG weight, so when even one goes in, such a disproportionate ratio inevitably crops up.

Bernd Leno

Our new shot-stopper faced 337 shots in the Bundesliga last season, as he played the full 90 in all but one match for Bayer Leverkusen. In that time, Bernd Leno allowed 40 goals. His expected goals against totalled 33.48, so he allowed about six-and-a-half more goals than expected in the league last season.

Again, it is normal for such a disparity to exist. However, compared to the oft-maligned Petr Cech, Bernd Leno seems second-best. After all, the Bundesliga is not packed full with world-class talent like the Premier League and the former Leverkusen man’s xGA to actual goals ratio is worse by a factor of more than two.

Other Considerations

Like other stats, xGA shouldn’t be taken as gospel on its own. Simply put, there is no statistic that can completely predict just how good a player is compared against another, especially between two leagues. So, let’s have a look at another consideration in the Cech v Leno debate.

If we divide Cech’s 365 shots faced by his 48 goals allowed, we find that on average he allows one goal per 7.6 shots faced. If we divide Leno’s 337 shots faced by his 40 goals allowed, he gives up one goal every 8.425 shots. So, by this metric, Leno gains the upper hand.

Then again, we must not forget the fact that the Premier League is the league with the highest parity in the world. In other words, there is very little to separate the various clubs in England and Wales as far as squad quality goes. So, Leno’s numbers will likely change a bit when he takes the plunge next season.

New Number One?

If we do see Leno’s shots to goals allowed ratio drop, he should be somewhere in the same region as Cech. However, what if his xGA to GA ratio also slips? Then, he would be below Petr Cech’s level right now.

While neither of these metrics can really predict how well either ‘keeper will do next season, especially with a new-look Arsenal defence, they do put in question the seemingly-set in stone decision of Leno replacing Cech.

Rather, he may take this coming season to learn from the veteran, much like Wojciech Szczesny did at Juventus this season before Gianluigi Buffon stepped down. After all, many players need time to adjust to the Premier League. Why not give Leno the same treatment?

The only real argument for handing him the job right away is that Cech was poor last season. However, the statistics suggest that the Cech v Leno debate is much closer than we thought.

Who will start for the Arsenal next season? Don’t act too surprised if we see a familiar face between the sticks, at least in the beginning.

Main Image Credit:
Embed from Getty Images