Once again, Josh Kalk has some good things brewing on his blog. He’s working on a clustering algorithm to distinguish pitch types for all pitchers, and he has player cards up for almost 300 pitchers. He’s seeking input to improve his algorithm from the first pass.
According to Josh, one of the worst performances of the algorithm was for Greg Maddux, so I thought I’d try out my tools on Maddux and see what I found in terms of pitch types.
My conclusion is that Maddux throws mostly two-seam fastballs (67%), a lot of changeups (21%), some cut fastballs (10%), and an occasional slider (1%) and curveball (1%). This more or less agrees with scouting reports, although you can find mention of Maddux throwing just about every pitch under the sun other than the knuckleball. For example, his Wikipedia article will tell you Maddux throws the splitter and the screwball, but I found no evidence for either in the PITCHf/x games in the 2007 season. On to the graphs…
Let’s start with what’s fast becoming my bread and butter, the pitch speed versus spin direction graph. I’ve color-coded the pitches in this graph based on my conclusions from all the data. I don’t claim that they are all easily identifiable based solely on this first graph. (All pitch speeds are normalized to y0 = 50 feet.)
The curveball is the easiest to identify. At 70-76 mph, it is the slowest pitch, and it’s the only one with topspin, with a spin direction of 50-100 degrees.
The slider is also fairly easy to distinguish, although I had to work a little at the exact boundaries between it and the cutter and changeup. The slider runs 79-83 mph, with mostly backspin and a little sidespin, corresponding to a spin direction of 120-180 degrees.
Maddux’s three main pitches are a bit tougher to separate. Let’s start with the changeup, whose most prevalent characteristic is its slower speed 78-83 mph, with similar spin direction to the fastballs. It has a spin direction ranging from 190-270 degrees, from mostly backspin to mostly sidespin.
Next, let’s go to the fastballs, the cutter and the two-seamer. From the speed vs. spin direction graph, you can tell that there are probably two separate fast pitches, but it’s hard to tell exactly where the line between them would go. Also, we can see another interesting fact. Usually the harder fastball is a four-seamer on the left, with more backspin (i.e., closer to 180 degrees), and the slower fastball is a two-seamer on the right, with more sidespin (i.e., shifted somewhat toward 270 degrees). Maddux doesn’t have that arrangement. His harder pitch is on the right, which is where the two-seamer should be. Based on scouting descriptions of Maddux’s repertoire, his main fastball is in fact a two-seamer, and he also throws a cut fastball. A cut fastball is usually a little slower than a four-seamer or two-seamer, so that correlates with our mystery pitch on the left half of the fastball grouping. In addition, the cut fastball typically has some slider-like characteristics, so it makes sense that the cut fastball would be found toward the slider side of the spin direction (i.e., toward 180 degrees and lower angles). So I think there’s good evidence to believe we’ve identified a two-seam fastball and a cut fastball on the graph.
Finding the boundary between the two will take us on a tour through some other graphs which will also help us define the changeup a little better and reaffirm our identification of the slider and curveball.
First, let’s visit an old standby graph, the speed versus horizontal break.
In this graph, the curveball is clearly evident again, as the slowest pitch with the most break away from a right-handed hitter. There is a group of pitches 78-83 mph also with a positive horizontal break, although slightly less break than the curveball. This, of course, is a signature of the slider. The changeup group is pretty readily identifiable here as the pitches 78-83 mph with negative horizontal break (in toward a right-hander). We can see some thinning out between the two-seamer group on the right and the cutter on the left of the fastest pitches. The boundary between the two is very smeared and hard to delineate on this graph. At least some of that smearing may come from the fact that we have three different y0 initial distances represented in our data set, and the closer y0 is set to home plate, the less break we will measure on the pitches.
I don’t see any evidence for a screwball on this graph. A screwball should be a very slow pitch, like a curveball, but breaking in to a righty, opposite of the curve. There are no pitches slower than 77 mph on the left side of the graph, hence, no sign of a screwball.
Next on tour comes the speed versus spin rate graph. It turns out that spin rate is a very useful parameter in helping us separate two-seamers from cutters and changeups.
The two-seamer generally has a faster spin rate, mostly in the 1500-2500 rpm range, but with some significant tails at both ends. The cutter and the changeup have slower spin rates, mostly in the 500-2000 rpm range. There is some overlap between the spin rates of different pitches, but it is a helpful tool in our pitch classification tool box.
Another graph we can make is spin rate versus spin direction, and this one is useful mainly for identifying two-seam fastballs that might otherwise look like borderline changeups. I didn’t find it very helpful in telling the other pitches apart.
It’s possible there are some splitters hiding out on the extreme right edge of this graph in what I’ve labelled as changeups. If there was a separate grouping hanging out farther to the right, as Papelbon’s splitter did, I’d tend to believe they were splitters, but at this time, apart from any other evidence, I don’t see a reason to believe they aren’t all just changeups.
Finally, we can look at vertical break versus horizontal break. This is the graph presented in Josh Kalk’s player card for Greg Maddux. You can see the great big blog that his algorithm couldn’t separate. I’ve nicely color-coded the pitches, so you can see there’s some order left-to-right, but they’re still pretty much a mess.
Ugh! Other than the curveball, I wouldn’t try to pick anything out of that graph alone. However, it was useful in identifying a few more two-seamers that were trying to masquerade as changeups.
So that’s the story on Maddux and his five pitches. The speed vs. spin direction graph once again comes through as the star, but this time it needed more help from its friends.
Of course, there are more interesting things in the data, for Maddux or for any pitcher, beyond just classifying their pitch types. Which pitches does Maddux prefer to throw to lefties or righties? Answer: he throws the cutter more to lefties (15%) than to righties (6%), and with righties he relies more on his two-seamer instead. Which pitches does he throw in various counts? How does he locate them? Which pitches get swings and misses and which ones see more contact? Which pitches turn into home runs most often? Et cetera. These will be left as an exercise to the reader.
Or, what the heck, do what I do and move on to another topic before this one is even cold.