Batter-pitcher data is overrated

Ron Washington and Tony La Russa should not let themselves be fooled by a few at-bats' worth of data. Paul Sancya/Pool Photo/US Presswire

With the St. Louis Cardinals facing elimination, Game 6 will be an all-hands-on-deck endeavor. Both managers are scouring their rosters for any potential advantage, and as part of that effort, they'll probably be referring to historic batter-pitcher matchups. Should Cardinals skipper Tony La Russa lean heavily on a player like Octavio Dotel, who has historically done well against Rangers hitters such as Adrian Beltre and Michael Young? Or should he opt for the players with the best overall performance, regardless of what the matchups say?

Let's say we want to predict the outcome of a particular batter-pitcher matchup. I'm going to lean heavily on true average, which is scaled to look like batting average but captures a player's total batting value. (A player gets a little credit for a walk and a bit more for a single, all the way up to a home run.)