It never evens out
We’re often told that luck will even out over a season. After all, a year is a long time, and it seems absurd that one team would repeatedly have things go their way or against them.
However, this misunderstands the true nature of ‘luck’. True luck, or randomness, is blind to what happened before, and can go either way in the future. The fact that a team might have had a few games where they were ‘unlucky’ – perhaps they’ve repeatedly been denied by unusually good goalkeeping, or have seen their opponents score multiple low-probability attempts – doesn’t mean they will enjoy some good luck in the future, that they are ‘due’ some good fortune. That run could continue well past the length of a season.
One way to visualise this is to look at the FA Cup. In each round until the semi finals, clubs have a 50/50 chance of getting drawn to play at home, which is clearly preferable. Of the current ‘big 6’ clubs, some – like Chelsea, Man United and Tottenham – have been lucky in this respect, getting far more home ties than away, while others – particularly Man City, but also Liverpool – have been unlucky. Even after 250+ cup draws, and over 100 years of matches, there isn’t a universal force that ‘evens out’ the luck.
What’s also apparent is how streaky good and bad luck can be. As highlighted, Arsenal were once drawn away 8 times in a row, ‘bettered’ only by Spurs’ 9 times in the 1950s. On the flip side, Man United were once drawn at home 9 times in a row. When it comes to actual football matches, we refuse to believe we could go half a dozen games in a row where we’ve been unlucky (or indeed lucky) – but that’s the true nature of randomness.
The key of course is trying to establish what has been bad (or good) luck and what has been bad (or good) performance. Our Performance League allows us to do this; it helps cut through the noise and establish whether the current run of results is powered by a random streak of good or bad luck in key incidents, or due to underlying performance.
The league table almost always lies – if luck doesn’t even out over 200 matches, it certainly wouldn’t over a season.