Chelsea’s defensive and set piece issues part one: What do we know?

Chelsea’s identity for the better part of the last 18 months has been defensive solidity, even though cracks in the defense began to appear as early as Matchday five of last season, Thomas Tuchel’s men managed it last season and still finished this season with very good defensive numbers. Before going further, some things need to be established. The first is if the Blues even have defensive issues. So what do we know about Chelsea defensively at the moment?

According to FBRef, CFC allowed 2.7 shots on target per 90 minutes in the 2020-21 season. The following season they weren’t as strong, but they still managed to keep shots on target at them to 2.84 per 90. 2.71 shots of target per 90 was the second-fewest tally that season and 2.84 was the third-fewest the following season.

This season, the Blues has allowed 27 shots on target at them. This means the Blues have allowed 4.5 shots on target per game. This tally ranks them 13th in the league for this. Southampton, West Ham, Leeds United, and Crystal Palace have allowed fewer shots on target per 90. This is the first indication that something is wrong.

Last season, Chelsea conceded 0.84 goals per 90. This season? 1.5 per 90 so far. Chelsea has not only been allowing more goals per 90, but they’ve also been allowing more shots at them per game, and from more dangerous positions. In the 2020-21 season, Chelsea kept the opponents shooting from 18.8 yards to goal on average. No team kept their opponents shooting from farther on average.

The following season that number reduced to 17.5, but that was still good enough to rank them 3rd best. This season their opponents are shooting from 15.5 yards out on average, which is good enough to rank them…joint 14th…with Leicester City. I could go on, but at this point, it’s painfully obvious how bad the Blues are defensively.

In addition to this, Tuchel’s men have been horrendous when defending set pieces this season. First, let’s compare. Last season, according to UnderStat, Chelsea allowed 79 shots from set pieces, and totaled 5.23 expected goals, averaging 0.07 xG per shot. They conceded just four set-piece goals from 38 games. Only Manchester City conceded fewer set pieces goals than the Blues. This season, not only are the Blues allowing more shots per game from set pieces, but the shots are twice as dangerous.

Chelsea has allowed 20 shots from pieces this season, with a total of 2.75 xG so far. This means that the Blues are allowing 3.3 set-piece shots per game, compared to 2.1 last season. This also means that Chelsea is averaging 0.14 xG allowed per set piece shot. 0.14 xG from a set-piece shot is quite high. To top it off, the Blues have already conceded four set-piece goals. They’ve only played six games.

It’s now glaring how bad Tuchel’s men are at defending from open play and set pieces, so what’s the cause? Find out in part 2.