Chance, Statistics, And The Game

One of the compelling aspects of baseball is how the whole enterprise skates on a mirror of luck. At the major league level, differences in talent are slight, and it really takes much of the 162-game season to sort out the pecking order among teams. Perhaps because so much of the game takes place in discrete events—pitch-by-pitch, batter-by-batter, out-by-out—statistics has been a large part of the game. Terms like batting averages, on-base percentages, and earned run averages make up the common idiom.

I recently read Curve Ball, by Jim Albert and Jay Bennett, a book that takes a look at the plethora of statistics in baseball from the point of view of a couple of academic statisticians. It’s an excellent introduction to thinking probabilistically about baseball. Some numbers are meaningful, some are not. Often broadcasters will say things like: “His lifetime batting against Jamie Moyer is 4 out of 11”. Even though this represents a batting average of .364—very high—it is a statistically meaningless ratio since with so few at bats the result is probably due to luck. Other times intuitions lead managers quantitatively astray. Albert and Bennett give the example of Barry Bonds being walked intentionally so often in the 2002 season (a pattern which has persisted in this season). Despite Bonds’ immense home run threat, when one goes through the play-by-play probabilities, it turns out in terms of expected runs that one is better off pitching to Bonds rather than putting him on intentionally in almost all situations.

Baseball is a game where the unlikely turns commonplace, given all things that can occur. How often does a team score 10 runs in a single inning? Not very often, but the Giants did it last night in a game against the Houston Astros.

The Red Sox will be the AL wild card team unless a) they lose all of their final four games of the season and b) the Seattle Mariners sweep the Oakland A’s in their final series this weekend. Let’s hope that unlikely combination doesn’t come to pass.