Aaron Hill Follow-up

There were so many good questions raised in the comments section of my post yesterday on Aaron Hill that I thought addressing some of them deserved a follow-up post. The bulk of the questions come from former BtB overlord Sky Kalkman:

Would love to see some further breakdowns. Did Hill see more or fewer pitches over each part of the plate (or outside)? Did he see different types of pitches, and different locations of different pitches? Did he swing at certain pitches/locations more often or less often? Did pitchers’ approaches change throughout the year?

Addressing Sky’s first point:

Yes, it does seem that pitchers pitch farther outside to Hill. The peak location is a good third of a foot farther away from Hill than to the average righty. Based on the results of yesterday’s post, this is a good idea: Hill crushes those inside pitches.

Skipping to Kalkman’s question about whether Hill swings at certain locations of pitches more than others:

Generally Hill has a higher swing rate than average righty and this is partially true for middle-in pitches, but as pitches get farther away from him he swings at about league-average rate. So it does look like Hill swings more often at the inside pitches that he has the most success with.

Sky’s last question was, “Did pitchers’ approaches change throughout the year?” This is very interesting. If you look at Hill’s FB% numbers you can see that he has been seeing fewer and fewer fastballs since 2006. But if you split it out by month for 2009:

March/April  .525
May          .550
June         .519
July         .572
August       .596
Sept./Oct.   .590

For some reason, in July, pitchers reversed this trend. After he had already crushed 19 HRs through the first half of the year pitchers started throwing fastballs to him more often. I poked around some more, but could not find a big change in where those pitches were thrown. This is an interesting trend and something that could be looked into further.

Ewan, another commenter, suggests:

One thing I noticed about watching Hill a lot last season is he is very good at fouling off pitches on the outer half for someone his size and who used a heavier bat. Because of this he almost forces the pitcher to throw him something a bit more hittable.

Here is the fouls per pitch by horizontal location:

This does not look to be the case. Hill does foul off a lot of inside pitches — which makes sense because he pulls them so much — but on outside pitches he fouls off pitches at about a league-average rate.

Finally, Vivaelpujols had a great suggestion:

Maybe you could also chart the vertical location in the strike zone, as a function of the depth of the plate. So home runs on pitches around 3.5 pz would extend to the furthest part of the square part of the plate. Home runs on pitches at 1.5 pz would only extend to the front of the plate.

What do you all think? I like it. Most of his HRs are in a fairly narrow band, but he has that one HR that was relatively up in the zone.

Thanks to all the commenters for their insightful observations and questions. Obviously even this still just scratches the surface. I have ignored an analysis of the height of the pitches, beyond this most recent HR graph; looking at performance and location of each pitch type separately; and a host of other questions.