An old baseball proverb says you shouldn’t check the MLB standings before Memorial Day. In my own version of this, I call it the 50-Game Rule. And while one might formulate it in a nuanced way, we can summarize it quickly. Don’t check the standings before your team plays 50 games!
Conveniently, that happens sometime around Memorial Day. And I use it every season to evaluate the Yankees.
However, I recently read the book Extra Innings, published by Baseball Prospectus. It covers stats-based answers to many of the common questions baseball fans and analysts ask. Among other questions, they asked how many games a team needs to play for us to predict its final record.
The answer: only 17 games! After 17 games, you can predict a team’s final record better than chance. But in order to get much more in-depth predictive value – in order to predict a team’s final record more accurately than looking at its past couple of seasons – the team needs to play 48 games.
Notably that hits very close to the 50-Game Rule. And so, the rule still works. More or less. And, of course, as a Yankees fan, I’m not interested only in predicting their final record. I want to know whether they’re a World Series contender. Surely that requires a larger number of games.
