The Curious case of Mohamed Salah
Since his Player of the Year winning season of 2017/18, Mohamaed Salah has divided opinion. In the last 14 months he has continued to be the biggest direct contributor to Liverpool’s attack with 46 goals and assists across the Premier League and Champions League (Mane 35 and Firmino 31) yet the fans seem to be favouring his two strike partners.
@footballstuff posed the question 5 days ago, before Mane scored against Leicester: “The best player in Liverpool’s front three is ___” . The results were categorically anti-Salah with 78 choosing Mane 58 Firmino and just 8 Salah.
Scouts and football fans are often divided on the role of data in assessing players but for attacking players the two approaches tend to converge over time. So why are the eye and data at odds in this case?
As an “undercover” Liverpool fan I have watched all but one of their games this season and despite believing in the value data has in assessing players, our player model has Salah second in the world, I find myself agreeing with the popular opinion. Mane and Firmino are both easier on the eye, they appear to protect the ball better and make superior decisions on when to dribble, pass and shoot.
In football, as with many decisions in life, there is a trade-off between risk and return. Players are continually deciding between high risk/high return: shooting, making an incisive pass or taking a man on and low risk/low return: protecting the ball and making safe passes. In the case of Liverpool’s front 3 perhaps the eye is better at working out which players are optimising this trade-off
To try and answer this question, the graph below charts the relationship between loss of possession (unsuccessful touches plus dispossessed) and non set-piece goals and assists per 90 minutes for all of Liverpool’s most regular starters over the last three seasons in the Premier League.
If we consider the trend line to measure “efficiency” in decision making, Salah has moved from efficient in 17/18 to inefficient in the last 14 months while his front three teammates have stayed very close to the line for the last two full seasons and have started this season efficiently. Salah is taking the same sort of risks as he did in his first season but his production has significantly fallen. We can attach all sorts of narratives to this: he’s trying too hard, his confidence is lower, oppositions defenders have worked him out, but the underlying change in this relationship: from “efficient” to inefficient” could be why he is harder on the eye and less valued by those watching him than Mane and Firmino. If he took less risks his output may reduce but the total attacking output of the team may increase?
It can be hard to quantify the impact players have on each other but investigating rather than dismissing qualitative opinion could certainly help us in asking the right questions of data and better assessing the overall contribution of players to their team.