Watching Rich Hill pitch reminds me of watching Barry Zito and I'm sure I'm not the only one who sees the similarities. Both are tall left handers with big, looping curveballs, but they have more in common than their physical appearances. Both pitchers are extreme fly ball pitchers, with 61% of balls in play against Zito in 2007 being fly balls and 65% for Hill. Despite the platoon disadvantage, left handed hitters have actually posted better offensive numbers against Zito and Hill than right handed hitters have. Their careers haven't followed similar trajectories, Zito made his major league debut at age 22 and had a Cy Young by 24, while Hill pitched in the minors until he was 25, hampered by injuries, but both lefties have a similar repertoire of pitches and appear to pitch in a similar fashion. Furthermore, the curveballs thrown by the two are practically begging to be analyzed via Enhanced Gameday. I've wanted to look closer at Zito since I had noticed his unique release point during the 2006 playoffs (more on that in several paragraphs) and comparing his curveball to Hill's was high on my to-do list for Gameday projects, so I figured I'd knock off both things in this article.
First off, here's a chart showing Barry Zito's start on May 15th in his return to Oakland. Zito struggled in this start, going four innings, while allowing seven runs on seven walks and six hits. From this chart you can see a couple of basic features of Zito's pitches. His fastball is pretty straight, although it does have some movement in on left handed hitters, the normal direction for a left handed pitcher's fastball to move. I'm not very confident in my identification of his slider and changeup, but based on what I have, the slider moves in on lefties, while his changeup moves slightly away. Zito's curve is the pitch I really want to look at in this article, so it was rather disappointing to see that Zito only threw 11 in the game. The curve ends up slightly more than 10 inches lower than a non-spinning pitch would, evidence of the tremendous topspin Zito imparts on his curve. Is a 10 inch "drop" an impressive number? The only way to check that is to examine other curveballs.
Before I move onto Rich Hill's curve though, I wanted to look at Zito's release point. During the 2006 playoffs, I noticed that Zito's release point was much closer to the center of the pitching rubber than I would have thought a left hander would be. His release point was very close to that of a right handed pitcher, and I speculated that it could be the reason left handed hitters had success against him. Here's a chart comparing his 2007 release point to his 2006 playoff release point, as well as the release point of Dan Haren and Joe Kennedy for perspective. All four release points were captured in Oakland, with the 2007 ones from consecutive days in an effort to control for park changes.
Even after accounting for the different versions of technology used, in 2007 Zito still releases the ball close to the middle of the rubber, but he's not as extreme as he was in the playoffs and other pitchers actually have similar release points.
Getting back to Hill, here's a chart showing his pitches from his start on May 22nd in San Diego. Despite striking out eight batters, Hill allowed five runs in six innings and took the loss in this particular start. Hill throws three or four pitches, clearly a fastball and curveball, as well as possibly a changeup and slider. I have the same uncertainty with classifying Hill's changeup and slider as I did with Zito and in the end I called one of the groups his changeup, while calling the other unknown. Looking at Hill's fastball, it has similar horizontal movement in toward left handed batters as Zito's had, although Hill's had a wider range of breaks. Even though Hill's fastball was faster, Zito's fell less vertically, possibly indicating greater backspin on the ball for Zito.
Hill's curveball is tremendous. The biggest difference between his curveball and Zito's is that his has more horizontal movement. In addition to breaking 12 inches down, Hill's curve moves roughly seven inches away from left handed hitters. Zito has the same drop on his pitch, but only gets three inches of movement away from left handed hitters. With everything else (pitch speed, release point, and vertical break) being just about equal, a curve that breaks laterally as well as vertically is harder to hit than a curve just moving vertically. The horizontal break also helps classify the curveballs from the hitter's point of view, with Zito's being 12-to-6, while Hill's is more of a 12-to-7 or 8.
Name Pfx_x Pfx_z Speed Zito -3.0" -11.3 72 MPH Hill -7.1" -12.3 74 MPH
The chart above shows the median values for several variables that describe Zito and Hill's curveballs. Do other pitchers throw similar types of curveballs? After looking at some pitchers who throw curveballs (and doing a little fishing in my database) I found several pitchers that threw comparable curves, but Zito and Hill were still unique. The chart below shows the median values for the pitchers I looked at.
Gil Meche had a very similar curveball to Zito and Hill, although he didn't have as much horizontal movement and threw only 13 of them in the start I examined. In this chart, negative pfx_x values indicate movement in to right handed hitters. Bronson Arroyo had the most horizontal movement of any curveball, but interestingly, actually had his curve end up higher than a non-spinning pitch would have. Either he was hanging his curve on May 16th, or there was something wrong with the tracking system in San Diego on that day.
Obviously Hill and Zito have very unique curveballs. Even after looking for pitchers with the greatest vertical drops, I couldn't find other pitchers with similar curveballs. One thing I would like to look closer at is which pitches Zito and Hill actually get their fly balls on. Are the fly balls a direct result of curveballs or are they the result of a general pitching pattern? I don't have enough curveballs in my database from Zito and Hill to really get a good read on it yet, but I would guess the fly balls are more a result of a pitching pattern than actual pitches.
I had a couple of things I wanted to mention before I finished. I have more data for sinker ballers now, with Webb having a couple of starts and Wang making his debut in an Enhanced stadium. I'm going to look at sinkers again in the future, and hopefully should have something new to say. I also noticed that Wakefield had several starts in Toronto, also an Enhanced stadium, and looking at his pitch charts, its not surprising that nobody can hit him when his knuckleball is working as the break values on his knuckleball look virtually random. Certain hitters also finally have enough enhanced pitches that I can look at batting average on balls in play from the hitter's perspective and have it mean something.