James Tozier posted this on twitter:
— James Tozer (@JCDTozer) May 11, 2017
And combined with the numbers I saw doing my By the Numbers piece yesterday
that I was prompted me to look at Arsenal’s big chances created v. big chance conceded since Arsene Wenger invented the back three system. Those numbers turned out to be, big chances created 9, big chances allowed 11. Or 1.5 BC created per game 1.83 BC conceded per game.
And so then I looked at shots for v. shots against: 65 shots for, 81 shots against. Or 10.8 shots created per game and 13.5 shots conceded per game.
And the same story showed up in shots in prime for and against: 11 SiP for and 15 SiP against. Or 1.83 SiP created per game and 2.5 SiP conceded per game.
None of these are the kinds of stats you’d expect from a top quality team. Top teams dominate the opposition in those categories, not the other way around. So, I ran the numbers through my expected goals formula and produced similar numbers to James’ Tweet.
|Man City FAC
What’s happening here is that Arsenal’s new system is creating fewer chances for Arsenal than season average (-3.6 per game average) and creating fewer high quality chances that season average with Arsenal down from 1.8 big chances per game average to 1.5 big chances.
Worse, Arsenal are allowing the opponent more shots than average (+2.3) while also allowing the opponent an increase in high quality shots; opposition big chances per game are up from 1.6 to 1.83.
But the reason why Arsenal are winning is because
What’s happening here is that Cech is saving Arsenal. He’s saved 4 big chances faced and 8 more shots in prime on target. That accounts for about 4.5 goals saved by my formula. And you can probably remember the chances he saved: that shot by Wayne Rooney after Holding’s poor backpass, Cech’s save on Harry Kane after Ox gave the ball away leading to a breakaway chance, Cech’s save on Alderweireld’s header, his save on Mahrez’s volley, Silva’s header, Aguero’s shot from close range, and his block off the line against Middlesbrough. He’s been immense in these last few weeks, despite Arsenal’s midfield and defense leaking chances.
Ironically, this is exactly what happened in the six months prior to Wenger discovering Francis Coquelin. Once he installed Coquelin in midfield, Arsenal’s defense got more robust. But since dropping him this season Arsenal have gone from a team which allowed few big chances and few shots in prime to a Liverpool-esque side which allows the opposition to have their way with the back line. Arsenal are now the most profligate defensive team of the top 7 and that hasn’t been stemmed by the addition of a third center back. If anything, it looks like having a third center back is actually limiting Arsenal’s attack, at least it looks like that in terms of shot creation.
Wenger has indicated that the back three is a temporary fix and whether it is simply psychological, it has worked in terms of actual points on the board and not just “expected” goals. Even if Wenger persists with this formation I still think the long-term solution is a midfield with at least two players who can (and do) perform at high levels both in and out of possession.