It’s sometimes fair to wonder if the punishment of a penalty really fits the crime that led to it being awarded. Thanks to expected goal models we can prove the point.
FBRef gives spot kicks a value of 0.79 xG, as just shy of four out of five are scored. Liverpool has only had two non-penalty chances of at least that value in league or Europe this season; tap-in goals for Cody Gakpo and Ryan Gravenberch against Wolves and Union SG respectively.
It’s really hard to otherwise generate chances of the value of a penalty. To get one for a foul on the edge of the box (as Liverpool got against Bournemouth) or a questionable handball (which was not the case against Everton) can almost feel like an injustice. Then once they’re awarded, the odds are heavily stacked in the attacker’s favor, as the expected goal data illustrates.
Some players, such as Mohamed Salah, are better than average too. When the Egyptian stepped forward to take his first Merseyside derby penalty on Saturday, he did so with an 82.4 per cent success rate from the spot for Liverpool.
Goalkeepers can give themselves a better chance of saving the penalty by doing their research into the kicker’s history. Jordan Pickford and the Everton analysts had clearly done this ahead of the derby, as the television coverage showed that his water bottle had some shot placement charts taped to it — a ‘trick’ that feels almost like it shouldn’t be allowed, but an increasingly common one nonetheless. The problem for England’s number one is that such data is largely irrelevant when you are facing Salah from the spot.
While shot placement can be recorded in incredibly detailed fashion these days, data provider Opta divides the goal into six sections: left, center and right for the top and bottom half of the goal. Using this classification, only three times across his 35 penalties for the Reds has Salah aimed for the same sixth of the goal for consecutive spot kicks. This method tips already sizeable conversion odds even further in the taker’s favor, as while it doesn’t mean the penalty can’t be saved, it reduces the value of knowledge of the player’s placement history.
It’s interesting to look back at when Salah has gone back-to-back with his goal zone choices from the spot, particularly in two cases. He missed his first penalty for the club when aiming for the low central area in a home game against Huddersfield in 2017. Remarkably, his second spot kick came against the same opponents and goalkeeper (Jonas Lössl) in the reverse fixture, and the Liverpool rookie doubled down by aiming for the same zone again. Was it a deliberate double bluff to fool the man between the posts?
Salah’s strategy earlier this year suggested it might have been. After consecutive penalty misses against Bournemouth and Arsenal— both of which were aimed to the left, high and low respectively — he went to the high center of the goal with a spot-kick against Tottenham, and scored. Three days later he had another opportunity from 12 yards, against Fulham, so what did he do? The number 11 went to the same zone, converted the penalty and the Reds won 1-0.
It’s all a question of mind games, of course, and Salah will have information on the habits of the goalkeepers he faces too. As his one penalty miss at the point of the 2019 Champions League final had gone to the low center of the goal, was it wise to pick that spot in such an important moment?
As he scored, it obviously was, but few outcomes determine narratives more sharply than whether a spot kick is converted or not. Nonetheless, it would be interesting to learn what Salah knew about Hugo Lloris’ penalty preferences. Not having to face them in the opening minutes of a Champions League final would be high on the list.
Only four men have taken more penalties for the club, but of course, there’s no data for the likes of Billy Liddell, Jan Mølby or Phil Neal, heroes of the past. But even if there was, would they have had the variety that Salah offers?
