Was Villa’s 7–2 defeat of Liverpool an anomaly?
For my first sports data project, I tackled Aston Villa’s 7–2 thrashing of Liverpool from earlier this season. This result came as a shock, even though Manchester United nearly went one better the same weekend, and it was tempting to blame it on the unusual circumstances caused by the pandemic (the late end to the 19/20 season and the lack of crowds this season). But I wanted to see if I could find an answer in the data.
My first step was to explore the performance stats to identify any outliers using the 1.5 IQR rule. I compared both teams’ stats for this game with the 19/20 Premier League season because I reckoned the sample size for the current season was too small.
The main data point that stood out in Liverpool’s case was the shots on target conceded. Villa recorded 11 which was much higher than Liverpool’s average of just under 3 in the 19/20 season. Should that come as a surprise? Villa’s average in the previous season was just short of 4, suggesting Dean Smith came with a specific game plan (more on this below).
Turning to Villa’s stats, other than shots on target, the number of counter-attacks caught the eye. They countered 14 times against Liverpool compared to an average of just under 3 in 19/20. When I mentioned this data point to a friend of mine who claims to be a diehard Red (he’s been to Anfield at least twice), he argued that most teams adopt those tactics against Liverpool. But as the graph below shows, that’s not the case (although it’s a popular tactic among some weaker sides, excluding Man City). What’s more, no other team executed the tactic successfully- Arsenal, Brighton, Villa, Bournemouth, West Ham, Southampton and even Man City lost away to Liverpool last season.
I didn’t really feel that I had unearthed anything groundbreaking from the performance stats, so I watched the highlights. Was the result purely an anomaly? I had forgotten that several of Villa’s goals were lucky- Adrian gave the ball away to Grealish in the box, who squared to Watkins for his first of the game, while the shots from McGinn, Barkley and Grealish were deflections. That said, Villa had to get into decent shooting positions in the first place.
One universal criticism aimed at Jurgen Klopp following the defeat was the defensive line played by Liverpool was too high. So did Villa come up with a plan to exploit it?
That prompted me to look at offside stats. Villa were only caught offside twice, whereas Liverpool’s opposition strayed offside an average of nearly 4 times a game in the 19/20 season. That average has fallen to just over 2 so far this season, suggesting opposing teams have adapted to Liverpool’s defensive strategy.
The next data point I explored was what Wyscout call ‘smart passes’ which are basically through balls. Villa attempted 9, which is much higher than the team’s average of 3.45 for the previous season. Digging into the player data, (somewhat confusingly Wyscout uses the term through balls), shows that Villa’s midfield played nearly double last season’s average in the defeat of Liverpool.
In fact, Grealish and Trezequet both made key contributions as attacking midfielders- Grealish’s expected assist was 1 versus Liverpool compared with a 19/20 season average of 0.2, while Trezeguet’s jumped from 0.06 to 1.32.
So what have I learned?
There are a few lessons here. First, even though Villa used it effectively, counter-attacking isn’t the way to beat Liverpool as shown by last season’s stats. What Villa seem to have done successfully is adapt their tactics to deal with Liverpool’s high defensive line. That responsibility fell to Villa’s attacking midfielders, particularly Grealish.
(All figures sourced from Wyscout.com)
