We're all aware of Bernazard's crazy opposite field hitting strategy, but to what extent did the plan affect individual batters? James already linked to a great piece at the Hardball Times, but I thought a closer look might be interesting.
First, let's use Jason Bay as a baseline, assuming Bernazard couldn't affect him in Boston. The black line is 2008 and red line is 2009. The higher the line, the more "likely" a ball was hit at that angle. -45 is the left foul line, 0 is straight up the middle, and 45 degrees is the right foul line. Since Bay is a right-handed hitter, pulling a pitch would be hitting closer to -45 degrees. You can see that the angle on his balls in play didn't change much from 2008 to 2009 and that he's a pull hitter, as we know.
In the THT article, Carlos Beltran had the most change in his pull %. Here I've represented switch hitters as left-handed hitters for ease of comparison. He was pulling the ball much less in 2009, although still somewhat a pull hitter.
Luis Castillo was singled out in the THT article as a player that didn't decrease his pull %. His graph actually didn't change that much between 2008 and 2009. Notice that Castillo is a opposite field hitter, if anything.
David Wright also had a noticeable change in pull %. His graph looks really bad, to the point where his pull-peak and push-peak are almost on the same level. I was actually surprised by this, because I noticed earlier that he was swinging at inside pitches more in 2009.
However, the correlation between pitch location and where the ball actually ends up isn't even close to 100%, so swinging at inside pitches isn't necessarily indicative of a pull approach.
What about Jose Reyes? Reyes didn't have too many at bats in 2009, so we might have issues with small sample sizes. However, to my relief, they didn't seem to have messed with his swing.
Both Daniel Murphy and Angel Pagan didn't play much in 2008, so again there's a lack of data for both, but I thought less established players might be more susceptible to tinkering by Bernazard. With the small sample size in mind, let's look at the two.
Oddly enough, Murphy might have been an opposite field hitter in 2008 but was pulling more in 2009. This matches anecdotal reports that he started pulling the ball more toward the end of last season.
Pagan's graph actually looks similar to Murphy's. He was pulling more in 2009, not less.
The results are more mixed than I expected. Wright and Beltran both appear to have noticeably changed the amount of pitches they pull. The Hardball Times article also shows that Tatis and Church also pulled less in 2009.
However, some players, like Castillo, Reyes, Murphy, and Pagan did not seem to have bought into the opposite field hitting "strategy". Castillo we can be reasonably certain of, since he acquired a decent number of plate appearances in both years. Reyes, Murphy, and Pagan are harder to decipher, since there's a serious mismatch in the amount of data available between the two seasons.