Follow Up On ERV Differentials

In all the statistics I presented in my earlier post arguing that the differences in HR, BB and K are largely determinative of a team's success, I did not present the correlation coefficients between the various differentials and games over .500. That's mostly because until Friday night, I didn't know Excel had a function that calculated correlation coefficients. Here they are:

HR Differential/Games over .500 = .7383 (a high correlation)
BB Differential/Games over .500 = .6781 (moderately high correlation)
K Differential/Games over .500 = .4507 (weak correlation)
ERV Differential/Games over .500 = .8569 (very high correlation)
ERV BB/HR Differential/Games over .500 = .8303 (also very high)

The bottom line is that you can pretty much throw out K differential as a key factor in team success. But like the Beane Count suggests, walks and home runs are the most important factors in a team's success.

How do our Nats' fare in these departments? They had a -40 HR differential and a -86 walk differential. Since Guzman/Castilla are pretty much a wash with Cabrera/Batista, I don't expect the HR numbers to improve for the Nats much. On the pitching side, Esteban Loaiza won't help the HR differential much...unless he's the 2003 version of Esteban Loaiza.