The Oakland A's were the first team to extensively (and successfully) use sabermetrics, or scientific, statistical baseball analysis. Through the best-selling book "Moneyball," by Michael Lewis, the A's successful utilization of sabermetrics became famous. Now, nearly half the teams in Major League Baseball use scientific statistical analysis, most notably, the Red Sox, who employ the legendary sabermetrician Bill James.
To demonstrate how sabermetrics can totally transform the way baseball is understood, I'm going to sabermetrically dissect Saturday's Dartmouth-Princeton playoff. The conventional wisdom regarding Saturday's playoff was that Dartmouth was the superior hitting team and the teams were roughly equal elsewhere on the field; in sum, Dartmouth was the favorite. This was wrong. The statistics tell us that Dartmouth was in fact an underdog.
Princeton was actually the better hitting team, but this was masked by the effects of the teams' home fields. Everyone knows that Coors Field inflates the Rockies' offense, but every park affects the game to varying extents. Dartmouth's Rolfe Field, with its tiny dimensions, inflates offense by about nine percent; Princeton's home park decreases offense by around 11 percent.
We can calculate adjusted OBPs and slugging percentages for the two teams by accounting for the effect of their home parks. Princeton increases from .390 and .450 to .404/.484, respectively. Dartmouth drops from .410/.497 to .404/.478, lower than Princeton's!
Princeton's pitching was also superior, even when accounting for park effects. On Saturday, each team had three pitchers who would pitch the vast majority of innings -- the two starters and a closer. Assuming each starter would pitch seven innings and the closers the last two innings of each game, we would expect that Princeton would surrender 3.63 earned runs per game, Dartmouth, 3.89.
But the effective difference was greater. Princeton's top pitchers struck out 1.7 more batters per game than Dartmouth's. More strikeouts equal fewer potential home runs and doubles in tiny Rolfe Field. With few walks and strikeouts, Dartmouth's pitchers relied on their defense, but in front of 360-foot long power-alleys, that was a dangerous, and ultimately fatal proposition.
Lastly, Princeton had the better team defense. This is measured through "defensive efficiency" -- the percentage of balls hit into play that are converted into outs. Princeton's defensive efficiency was 69.0 percent, Dartmouth's, 67.4 percent. This is a significant difference; it's the equivalent of a .016 difference between the teams' batting averages.
The Big Green, ostensibly the better team, was actually inferior in all aspects of the game. The Red Sox and A's use tools like these, and many that are infinitely more advanced, to understand and improve their respective teams and to win ball games.
