New York Yankees v Baltimore Orioles

Sometimes, simpler is better. Sometimes, mathematically gymnastics are required to extract good from evil and separate the informational wheat from the noisy chaff. Joe Lemire of has a great article today, on a simple measure for a different type of win expectancy: batters faced.

Lemire leans on the work and experience of former Orioles pitching coach and current director of pitching development Rick Peterson in unveiling the mystical properties of the number 39 – as in 39 total batters faced for a pitching team is often the difference between winning and losing.

The Orioles analytics department showed Peterson (who in turn showed Lemire) that the difference in winning percentage plunges when a team faces 38 batters versus 39 or 40 (home teams only used for this study, as they registered the required 27 outs). As Lemire notes, it seems intuitive enough: more batters faced means more base runners and more run-scoring opportunities.

Click through for the full breakdown of how the Orioles manage their bullpen with this number in mind, trying to avoid facing the heart of the opponents order a fifth time in a single game.

No better way to test out sound mathematical theory than with a little ad hoc Small Sample Size Theatre! How did this shake out for the 2012 season? Any outliers or reasons for concern? (Line indicates league average of 37.90)

TBF wins

Oddly, the architect’s own Orioles pop up as one of the biggest outliers. Perhaps part of the reason Baltimore didn’t blow their brains out this offseason trying to chase the 2012 dragon.

This information should not be taken as gospel, as it represents only one year and lacks crucial context such as “offense.” Good defense and pitching teams don’t always win, as evidenced by the sadsack Seattle Mariners failing to capitalize on their own efficient run prevention.

The Rockies will always be an outlier because of their ballpark but that…that just seems wrong. Again, the run environment in Colorado makes this screwy…or does it?

Logo change indicates pre/post humidor

Logo change indicates pre/post humidor

When the Rockies are good, they face fewer batters per game. It is just that simple. Pitching and defense always matters, no matter how many homers you think you can bash.

All in all, a very interesting piece you simply must read. So read it! Then check back: is there anything predictive in what we see above? Should Braves and Rays fans be ready for a bump in wins?

Team data courtesy of Fangraphs.