Put emotional attachments and club loyalties aside: what does the data tell us about the new Premier League season? And we’re not talking simple stats, we’re talking big data and bayesian artificial intelligence algorithms.
“Much information is input to our model, from at what point goals were scored in the game to how red cards affected the final results,” says Luis Usier, quantitative analyst at 21st Club, a consultancy that advises football clubs about squad evaluation and player transfers. That level of data allows analysts to build a world league table that ranks teams using the same objective criteria, from Indonesia’s Liga Prima to England’s Premier League. And, according to 21st Club’s world league table, Tottenham are currently favourites to win the Premier League. However, there’s a caveat: all the top six teams – Manchester City, Manchester United, Arsenal, Chelsea and Liverpool — have very similar odds. “We deliberately didn’t put a number on Spurs’ or anyone else’s title odds at this stage,” Usier says. “Our model rates Tottenham as the best team in the Premier League currently, but there’s very little separating the top six teams and a lot of uncertainty around new transfers, so the probabilities of winning the title are pretty evenly spread.”
Still, it seems that Spurs are being underestimated by the bookies. “If you put the Tottenham squad and transport them to Stamford Bridge and you took Chelsea squad and transport them to Wembley, the title odds would still be backing Chelsea just because they are Chelsea,” Chaudhuri says. “There’s a feeling in the markets that Chelsea just get the job done regardless who their players are. Whereas Spurs are notorious for messing it up, which they did when they finished below Arsenal in the last few days of the 2015-16 season.”
One of the factors underpinning Tottenham’s favourable odds is their goal-difference last season. “There were only three teams with a better goal difference in the past decade and they were very good teams,” Usier says. “The goal difference is a very useful indicator. Winning a bunch of games by one goal is very different from winning by a large margin. The goal difference gives you a sense of the dominance of the team and is a better predictor of future results than actual points.”
The 21st Club analysts also don’t believe that the Tottenham’s move to Wembley this season will affect the team. “Home advantage tends to increase in the last season in an old stadium and it decreases by about 12 per cent in the first season in a new stadium,” Chaudhuri says. “But it’s different in this case as there’s already some familiarity with the Wembley having played there last season for the European competitions.”
Other title contenders will face a different set of challenges. Both Chelsea and Liverpool return to the UEFA Champions League this season. Anecdotally, there’s a belief that European tournaments negatively affect domestic performance: just consider Leicester’s remarkable title-winning 2015-2016 season and Chelsea last year. Both teams won the Premier League without the extra burden of having to play in European competitions.
The 21st Club model bears this out. By looking at their core starting elevens and simulating the impact of rotation of the squad, they estimate that Chelsea and Liverpool will suffer an impact of three to six points in the title race. “Firstly, players get the extra time on the training field, get more rest, spend more time preparing,” Chaudhuri says. “Secondly, you have more injuries and increased rotation of the squad. European competitions mean that the team’s core players usually play around five to ten percent fewer league games.”
As for Manchester United, despite being considered the 11th best team in the world and the fourth in England, the prediction is that they will actually finish outside the top four places. Their problem is the defence: whereas Jose Mourinho’s defensive approach actually gives them a greater chance of beating their top rivals, it leaves them vulnerable to lose points against weaker opposition. “Low-scoring contests tend to favour underdogs,” Chaudhuri says. “Against a favourite, an underdog is much more likely to win a dour 1-0 than an open, exciting 3-2. We saw this time and again in last season. Instead of winning matches 3-2, or 3-1, United ending up drawing games when they struggled to breakdown the opposition.” Even though United have the talent to become an attacking force, Mourinho’s football philosophy is unlikely to change. “Five-four is a hockey score, not a football score,” he said in 2004, referring to an Arsenal win over Spurs. “In a three-against-three training match, if the score reaches 5-4 I send the players back to the dressing rooms as they are not defending properly.”
Manchester United’s signing of Romelu Lukaku won’t make much of a difference either, as he’s considered to be as effective as Zlatan Ibrahimovic, who left Old Trafford after just one season. Of course, Lukaku isn’t the only new face at Old Trafford. Manchester United also acquired defender Victor Lindelof and midfielder Nemanja Matic, spending a total of £101.75m on transfer fees. That sum, however, pales in comparison to rivals Manchester City, who have already splurged more than £210 million, making them the most profligate team in Europe, on course to beat Real Madrid’s £219.8m record spending. Some of their London rivals, on the other hand, have been thrifty in comparison: Arsenal have only spent £52m and Tottenham a grand total of zero.
This is the Premier League fantasy game you should be playing
But do new signings actually make a difference? According to their model, 21st Club’s analysts estimate that the impact of new signings is still quite low: 44 per cent of club-record signings fail to become part of the starting eleven in the first season. “Spending has gone up because revenues are going up and so consistently we see that spending is around 23 to 25 per cent of clubs income,” Chaudhuri says. “They’re not out of line with what they’ve been historically. It’s not a bubble. But there are certainly inefficiencies and we’re seeing clubs overestimating the impact that new signings can have and then potentially overpaying on some of their top players.”
This analysis is universally valid: 21st Club predicts that Neymar’s record signing will only add four points to PSG’s Ligue 1 tally and a mere five per cent increase in their chance of winning the Champions League. “It’s the same with most players,” Chaudhuri says. “They don’t shift the needle as much as much you’d expect, certainly in the short term. Now in, Neymar’s case, it might be a brand building. But most clubs pay top dollar and expect a player to transform the club. That rarely happens.”
Other big data Premier League predictions
60%: Odds of recently-promoted Huddersfield to be relegated at the end of the season. 21st Club’s World Super League model rates Huddersfield as the 36th best team in the country, only slightly above relegated Blackburn Rovers.
27%: Odds of Southampton being in the top 4 after six games.
16%: Odds of Everton being in the relegation zone after the same period. “It’s usually around this time that narratives start to form. However, at the end of the season, our model still rates Everton as being about three times more likely to finish in the top 7 than Southampton,” Chaudhuri says.