So David Pinto wrote an interesting article suggesting that Pat Burrell has a hard time hitting hard fastballs. Almost as if he read the very same article and sought to prove it wrong, Burrell crushed a 97 MPH Jonthan Broxton fastball last night. I’m certainly not saying that one at-bat proves Pinto wrong (that would be pretty stupid), but it did remind me of the kind of caution that we need to exercise with this kind of data.
1. Times Series are Dangerous – Whenever you look at the behavior of something over time, it’s really hard not to analyze it with “after this, therefore because of this” type reasoning. But we all know lots of examples where things happen after something else where causes are completely unrelated.
2. Isolated Pitch Analysis is Always Incomplete – Pitches work better in conjunction with each other. If a guy really appears to struggle with the change-up, it may be that he just has a hard time adjusting to a change up after he sees a good fastball. We should be cautious about concluding that a single pitch is a batter’s kryptonite, because he may actually just struggle with a certain sequence of pitches. Even Aaron Rowand could probably hit .500 off of breaking pitches if he knew that was all you were going to throw him.
I’m sure Pinto knows all this. He’s shown himself to be a very open-minded, humble analyst in the past. But it’s tedious for a writer to constantly caveat his work, so it’s a good idea for us readers to consume statistical analysis intelligently.
I think it will be one those interesting little bits of trivia to see if Burrell shows whether his trend of struggling against harder fastballs is meaningful or not. He’s off to a pretty good start.

