There has been a lot of discussion on Mike Wilner's blog
about whether the Managerial Changes made last June 20 had an impact. This will not answer this to the satisfaction of Mr. Wilner, as his explanation is that the changes are not due to Cito, Gino, et al, but simply due to the fact that the hitters finally got there act together. Fair enough. There is no way to test that assertion statistically, unless you were prepared to look at the hitting situational statistics to see if the batters were being more aggressive and swinging earlier in the count. One thing I can say, which is not in these slides is that bases-on-balls were down by more that one per game under Cito (p-value of 0.0005), without changing the OBP significantly, which suggests to me that the hitters were being more aggressive.
There is a typo in the above slide - it should be p = 0.0499 less than alpha = 5%. When I figure out how to replace the slide, I will do so. (I'm new to this blogging stuff.)