One of the most important roles that advanced stats can play in sports conversation is helping us to understand what’s real and what isn’t. Luck and randomness play such a large part of a given outcome — especially in the two sports I write the most about, college football and soccer — and over short periods of time, both your eyes and the scoreboard can lie to you.
With that in mind, I wanted to see which statistics are particularly predictive from one sample to another, and which stats from one season translate pretty well when looking ahead to the next. This sport is blurry compared to even a tricky sport like American football — at least football has stoppages and specialized 11-man units for offense, defense and special teams. But looking at what actually appears predictive and sustainable allows us to break things into compartments, key factors of sorts.
In my soccer writing over the past few months, I’ve randomly talked about how certain stats are predictive of success moving forward, because either they are stable quality measures, or proof that success in certain areas leaves you vulnerable to regression to the mean. As the 2020-21 season gets underway, I wanted to further explore what these stats can tell us moving forward. Here’s how I’ve found myself grouping them:
Efficiency and finishing factors. The basics (goal differentials, expected goals and whatnot) along with some situational extras. These are the main measures I’ve found that correlate well to the next season’s performance.
Turnover and field factors. Not the greatest title in the world, but go with it. Two of the most important factors in American football are turnovers and field position. Essentially, where you start your possessions and how frequently you’re giving the ball away at inopportune times. Those ideas work pretty well in soccer, too. Better, even.
Ball control factors. These are not as directly impactful as the factors above, but they remain predictive. In short, teams that control the ball better than their opponent tend to find more success. Yes, there are exceptions and yes, a possession-heavy style can leave you vulnerable to counterattacks and other maladies. But it’s still step one toward solid point totals. If you’re trying to win without the ball, you have to do a lot of other things well.
Regression-to-the-mean factors. Simply put, if you are a little too good in these categories, both you and those categories are likely to regress soon. Similarly, if you’re poor here, you’re likely to improve.
Now let’s get specific and put these stats to action. What can they tell us about the (extraordinarily long) season that just unfolded? What can they tell us about what’s to come? We’ll use the Premier League as our guinea pig before picking a champion in each of Europe’s big five leagues.
Jump to: Premier…