0-1. 1-0. 0-1. 1-0. For Leicester City, binary never looked so beautiful. Four successive single‑goal victories in March, followed by Sunday’s 2-0 win at Sunderland, have put the Foxes close enough to sniff the polish on the Premier League trophy. No wonder their captain, Wes Morgan, recently hailed the “momentum” of their magical run.
Momentum. It has become a word synonymous with Leicester’s season. Not only to describe their early form, Jamie Vardy’s molten hot streak and their attritional march to the title but also the intangible effect of confidence.
Lee Dixon put it more vividly than most when he equated Arsenal’s 1997‑98 run-in – when they won 10 games in a row to overhaul Manchester United – to “an out-of-body-experience”. In the dressing room, he admitted, he was “literally not caring about anything other than being excited because you know you are going to win”. Momentum, see.
Yet while it remains one of football’s great shibboleths, there is a problem – a lack of conclusive proof that teams and players get “hot” due to anything other than talent or luck.
A few years ago, for instance, the economists Stephen Dobson and John Goddard looked at every English league match between 1970 and 2009 – 81,258 games – to examine whether longer winning, unbeaten and losing runs were observed more often than would be expected by chance.
After accounting for team and opposition strength and doing some whizzy maths they reached a surprising conclusion. On average, sequences of consecutive wins and matches without a win end sooner than expected. In other words the momentum effect was negative.
It may be, as Goddard speculates, that players in winning teams become fixated on keeping the run going in a way that inhibits performance or that losing sides ramp up their efforts to stop the rot. But, crucially, a winning run does not appear to inspire teams to win future games more than their underlying strength would suggest.
What about the effect of momentum on players? In basketball and baseball there are ongoing disputes over whether players get a “hot hand” – with most studies arguing it is nothing more than statistical noise – but in football there is not the research in the first place.
Yet players certainly believe it exists. Strikers on a scoring run talk about the goal being as big as a jumbo jet, while a goalkeeper who makes a series of saves will feel almost unbeatable. The problem is how to quantify this.
Say someone is historically a one-goal-in-every-two-games forward but he scores in four successive games. Has he got hot? Or is it because he is facing a weaker opposition, taking more shots or getting a few lucky breaks? It might just be variance – the football equivalent of flicking a coin four times and it landing on heads every time.
Given the lack of data it is perhaps unsurprising that momentum sometimes becomes discussed in almost mystic terms. A Football Association publication, Momentum in Soccer: Controlling the Game, for instance, describes it as “the force that dictates the flow of a match: a hidden force because it is not always reflected in the score”.
One way potentially to assess this “force” is to examine Ruud Gullit’s view that a team missing a penalty suffer a psychological blow, which can impact on their performance for the rest of the match. Instinctively it makes sense. A penalty has around an 80% chance of going in. Missing one should hurt.
The football data expert Mark Taylor was asked to examine every Premier League match since 2005-06 where a penalty was awarded between 0 and 70 minutes, kicking out games where the rebound was converted and/or a red card was awarded – a sample of 68 games. To assess whether a team was demoralised from missing a penalty, Taylor used the betting odds at kick-off to calculate the relative chances of each side as well as the in-running odds just before the penalty was awarded.
Armed with that information, Taylor came up with a league points expectation for each side immediately before the award of the penalty and then ran a series of mathematical simulations. Surprisingly, perhaps, they indicated that teams who miss a penalty when scores are level actually tend to do slightly better afterwards than one would expect them to do based on their pre-game odds.
Perhaps Gullit was overly influenced by his experience as a player. In 1995, for instance, he played for Sampdoria in a match where Brescia missed a penalty when 1-0 up and lost 2-1 after a late David Platt double.
As Taylor points out: “It’s a fascinating example of how natural cognitive biases may lead you to think one thing, while data-driven analysis may make randomness a more compelling explanation. And people prefer the former to the nebulous latter.”
Of course there is much here that remains unexplored. Still, the next time someone mentions Leicester’s momentum point out that Manchester City and Arsenal also appeared to be on a charge earlier this season. City started with five successive wins without conceding a goal, while Aaron Ramsey and Arsène Wenger both invoked the M-word after victories over Bournemouth and Leicester in February, only for Arsenal to win only one of their next eight matches. What happened to their momentum?
