Friday, September 18, 2009
How many home runs would Pujols hit if he was pitched to like Juan Pierre?
Posted by Nick SteinerJuan Pierre has 13 home runs in over 6000 plate appearances in his career so far. That's not very good. In fact, Albert Pujols has hit more home runs this year in the month of June alone. Based off of that large discrepancy in power between the two, we can be pretty confident that pitchers are going to be much more aggressive when facing Pierre than when facing Pujols.
But what if they weren't? What if the two magically switched bodies, and Pujols suddenly saw life through the eyes of Pierre? For one, you would probably start to see some pitchers getting demoted for allowing 450 foot bombs to "Juan Pierre", along with some steroid allegations which would subsequently result in a "accountability" sermon from Ken Rosenthal. Secondly, before the pitchers caught on to the guise, you would most likely see a large increase in the amount of home runs hit by Pujols. How much? Well let's find out.
Using the wonderful Pitch f/x technology, which, believe or not is, probably not ruining baseball, we can see the location of each pitch thrown to Pujols this year. So, I split up the strike zone into 9 different zones, and figured out the percentage of (total) pitches thrown in each zone:
As you can see, he doesn't see a lot of pitches in the strike zone, with a Zone% of just 45.1% by my calculations (FanGraphs has him a 44.9%). League average is a little over 49%, so he really has been getting strike starved this year. You'll also notice that he's seen very few pitches on the inner third of the strike zone, with just over 10%. That seems rather smart for the pitcher when you consider Pujols' prolific bat speed.
The next step is to take a look at the percentage of pitches in each zone that Pujols has hit a home run:
Predictably, he's most efficient on pitches right down the middle, hitting over 8% of them out of the park. Other than that, he likes the high outside corner, the middle inside part of the plate.
You can reverse engineer Pujols' home run total this year using those two graphs. Multiply the percentage of pitches hit for home runs in each zone by the percentage of pitches seen in each zone by his total pitches seen that year. That's how you'll transpose his HR/Zone on Juan Pierre's pitch distribution.
First, however, we have to look at the distribution of pitches to Juan Pierre. I'll use the same method as with Pujols obviously, and I reversed the two sides to adjust for the fact that Pierre is a lefty:
As you can see, Pierre gets pitched to a lot more, as over 55% of pitches seen are in the strike zone. He also sees a lot more pitches down the middle, which would be nice for Albert.
Anyway, doing the process I described above, we can estimate that Pujols would have hit roughly 62 Home Runs so far this year if he saw the same distribution of pitches that Pierre did. Ridiculous.
Nick is a Cardinals fan living in LA. He also writes for Viva El Birdos. He welcomes questions and comments via email
Very neat idea, Nick. Thanks!