Chelsea should allocate most of their defensive recruitment budget on a replacement for Kepa Arrizabalaga as data suggest it would bring most significant improvement.
The 54 goals they have conceded in Premier League this season, might suggest that they would need a massive overhaul in their defence department.
They’ve conceded more goals than 10th placed Burnley, despite finishing in the top four, after all.
A big defender, a Liverpool’s Virgil van Dijk or Real Madrid’s Sergio Ramos-type defender would improve their defence significantly, yes.
But a defender of such calibre doesn’t just pop up out of nowhere in the transfer market, and at the current transfer market, there is arguably none of them available.
And if you look deeper into the statistics, Chelsea defenders have done their jobs relatively very well.
Statistics suggest Chelsea did well in limiting shots faced
Defenders’ primary job is to limit the quantity and quality of shots their goalkeepers face.
In the Premier League 2019/20, Chelsea conceded the second-fewest shots in the league (8.5 shots per game – Whoscored), just below Manchester City (7.4).
For comparison, the current Premier League champions Liverpool faced nine shots per game (third-lowest in the league)
In terms of limiting shots on target, Chelsea still ranked third (115 shots on target faced – FBref), just below Manchester City and Liverpool (both at 107).
It implies that Chelsea defenders did well in the quantity aspect of their job. But what about quality?
This is where Chelsea really struggled.
They were expected to concede roughly 0.35 goal for every shot on target they faced which ranked worst in the league.
For comparison, Manchester City and Liverpool had it at 0.30 and 0.29, respectively.
However, if you combine both quantity and quality, Chelsea still fared quite well with their goalkeepers expected to concede just 40.6 goals (PSxG), ranked fifth in the league.
Liverpool and Manchester City had it at 31.6 and 33.6, in comparison.
Underperforming goalkeeping let them down the most
It didn’t explain why Chelsea conceded about 20 more goals than those top two teams; this is where goalkeepers come into play and where they should focus their attention on this summer.
Kepa Arrizabalaga’s ranked 37th out of 37 goalkeepers in the league in terms of difference between expected goals allowed and actually goals allowed (-9.9 in PSxG+/- – FBref) and 21st out of 21 goalkeepers in terms of save percentage (54.5% – FBref).
As the data suggest, signing a good goalkeeper could potentially help Chelsea cut down their conceded goals by 10, or even more if it’s a top goalkeeper.