Johan Santana's changeup has been on my mind for the past week. Ever since I learned that if right-handed hitters make contact with the pitch, which doesn't happen very often, they tend to drive it, I haven't been able to stop thinking about it. Santana's changeup is said to be one of the best pitches in baseball, so I thought that in addition to creating a lot of swings and misses, this pitch wouldn't be beaten like a mule when it was put in play. I wasn't sure how the relationship between the swings and misses he got and the hits he allowed impacted the perception of the pitch but some comments on the article offered different ways to look at the changeup. One suggestion was to find the run value of every pitch to see which pitches are most beneficial, so thanks to Renè's idea, I did just that.

Finding the run value of a pitch is not as hard as I initially thought it might be. Using Tango's linear weights generator I found the run value of a single, double, triple, home-run and out. Using those values, I was easily able to find the value of each pitch for balls that were put in play, but I also needed to account for pitches that weren't put into play. To find the value of an average ball and strike, I converted the wOBA for each count into runs for that count, and then found out how much adding one ball changed those values for every count. I did the same thing for strikes, with the end result being that a ball is worth about .097 runs and a strike is worth about -.124 runs. There's a huge difference in the value of a ball or strike depending on what the count is, but I used these average values for my analysis because I didn't want to slice my already somewhat small sample of pitches into 12 smalled samples. As I continue to sift through this topic, I'm going to have to account for the different counts.

Below are the 10 pitches that saved the most runs in the 2007 season. In addition to the run value of each pitch, the Sw% (swings and misses/total swings) and SLGBIP (includes home runs) are also shown. I broke the pitches up by batter hand to give a more accurate portrayal of exactly who is impacted by a pitch.

Name            Pitch   N       Batter  LWTS    Sw%     SLGBIP
Brandon Webb    FB      460     R       -13.28  0.12    0.270
Jake Peavy      FB      456     R       -9.16   0.22    0.288
Chris Young     FB      363     R       -7.91   0.22    0.328
Kason Gabbard   CH      147     R       -7.72   0.36    0.182
Roy Halladay    FB      224     L       -7.36   0.07    0.250
Felix Hernandez CH      124     L       -7.27   0.23    0.069
Greg Maddux     FB      443     R       -6.89   0.05    0.430
Brian Bannister FB      289     R       -6.86   0.14    0.333
Dan Haren       CB      264     R       -6.81   0.26    0.309
Cole Hamels     CH      176     R       -6.70   0.37    0.308

Brandon Webb's sinker was most valuable pitch in terms of preventing runs last year, coming in at 13 runs saved vs. a league-average pitch. Other stud pitches fill this list, which was actually made up of more fastballs than I would have anticipated. However, since this is just total runs saved and fastballs are thrown so frequently, the results really aren't surprising. Finding the raw number of runs saved is going to highlight quality pitches, but it also is impacted by the number of times the pitch is thrown. If I want to look at the quality of a pitch, independent of how often it's thrown, LWTS per pitch is going to be much more informative. Here is a list of the best pitches by LWTS/pitch, for pitches that were thrown a minimum of 50 times. 

Name            Pitch   N       Batter  LWTS    LWTS/pitch
Matt Herges     CH      67      L       -5.95   -0.09
David Weathers  SL      50      R       -3.95   -0.08
Jon Rauch       FB      52      L       -3.78   -0.07
Ruddy Lugo      CB      59      L       -4.03   -0.07
Matt Capps      FB      68      R       -4.67   -0.07
Brandon Webb    CH      68      R       -4.23   -0.06
Felix Hernandez CH      124     L       -7.27   -0.06
Kason Gabbard   CH      147     R       -7.72   -0.05
J.C. Romero     CH      71      R       -3.36   -0.05
Brett Myers     FB      71      L       -3.11   -0.04

This list has some crossover from the first list, and the new list confirms that King Felix has a great changeup (vs. LHH), especially compared to other changeups thrown by right-handed pitchers to left-handed hitters. Kason Gabbard's changeup (vs. RHH) also makes an repeat appearance on the list, which is a bit of a surprise because I had no idea his changeup was that good. Changeups thrown to an opposite handed batter generally cost a pitcher .01 runs per pitch, but Gabbard, Hernandez and Matt Herges were all able to buck that trend last year. Webb is also on this list, but for his changeup, not his fastball. Webb actually has a higher ground ball percentage on his changeup than on his fastball, which helps to explain the inclusion of his changeup on this list, but it's interesting that while Webb's sinker is considered his money pitch, his changeup might actually be a more effective pitch.

Looking a little closer at Webb's pitch repertoire you can see the effectiveness of each of his pitches. He's tougher on right-handed hitters overall, although lefties have a tough time hitting his curveball. Against righties, his changeup is twice as effective as his sinker, although that could be because he throws it infrequently relative to the sinker. 

Pitch     N     Batter  LWTS    LWTS/pitch
FB      460     R      -13.28  -0.03
FB      517     L       2.15    0.00
-----------------------------------------
CH       68     R      -4.23   -0.06
CH       89     L       0.90    0.01
-----------------------------------------
CB       77     R       0.28    0.00
CB      112     L      -2.17   -0.02
-----------------------------------------
CT       67     R      -1.32   -0.02
CT       97     L      -0.77   -0.01
=========================================
Total  1487     -      -18.42  -0.01

One thing that piqued my curiosity when looking at this list of pitches was if the 18 runs that Webb's pitches prevented could be something larger. Was Webb 2 wins above average in the starts that he made in Gameday parks? Could those wins be directly attributed to his pitches? Webb's pitches prevented 18 runs over what a set of average pitches would have done, so his pitches could be said to be responsible for 1.8 wins more than an average pitcher. Counting the playoffs, Webb made 16 starts in stadiums with the pitch f/x system in place, pitching 113 innings and posting an ERA of 2.55. 113 innings with a 2.55 ERA in the NL makes a pitcher 5 wins above average in his starts at enhanced parks. Perhaps fielding made up the 3 win difference over this time period, or perhaps Webb leveraged his pitches effectively, throwing strikes when it was important and throwing outside the strikezone when it wouldn't hurt him too much. Exploring this topic in more detail probably deserves a whole column at some point.

Getting back to all pitchers, I wasn't very happy with the list of LWTS/pitch that I showed earlier. There were a lot pitches that had great rates but had only been thrown a handful of times, making me wonder if the pitcher had just gotten lucky throwing them. I'm sure Rudy Lugo has a great curveball, but he's only thrown it 59 times. I could have raised the minimum number of pitches, but that would eliminate the interesting pitches. The solution in this case is to regress the LWTS/pitch values toward the mean. Using the average value of every subset of pitch (fastballs thrown by LHP to LHH and fastballs thrown by LHP to RHH are examples of subsets) I did a rough regression which gave results that matched the general perception of pitches. 

Name            Pitch   N       Batter  LWTS/pitch (regressed)
Kason Gabbard     CH    147     R       -0.04
Roy Halladay      FB    224     L       -0.04
Felix Hernandez   CH    124     L       -0.04
Matt Herges       CH     67     L       -0.04
Cole Hamels       CH    176     R       -0.04
Scott Kazmir      FB    288     R       -0.03
Aaron Laffey      CT    226     R       -0.03
Bobby Jenks       FB    107     R       -0.03
Jonathan Papelbon FB    148     L       -0.03
Jonathan Papelbon FB    127     R       -0.03
Mariano Rivera    FB    187     L       -0.03

This list makes much more sense. Gabbard's changeup (vs. RHH) remains at the top, which is something that bears watching in 2008. The rest of the list is filled with most of the usual suspects, Cole Hamels' changeup (vs. RHH) lives up to the hype, Kazmir's fastball is up where you would expect it and Jonathan Papelbon's fastball is amazing. It's equally effective against both lefties and righties, which is impressive by itself, but its even more amazing that it's so effective against both types of hitters. The last pitch on this list is Mariano Rivera's cutter (vs. LHH), which is another pitch that has been on my mind recently. This pitch showing up is no surprise, and I wish we could have seen where it ranked when Rivera was on the top of his game. If you're wondering, Jared Burton's cutter, the closest thing Rivera's pitch has to a modern-dayclone, was the 12th most effective pitch in baseball, falling just outside of this list. He's someone else to to watch in 2008. Also, after doing the regression, Webb's sinker (vs. RHH) is slightly more effective than his changeup (vs. RHH).

So where does all this leave us with Santana's changeup against right-handed hitters? Compared to other left-handed changeups thrown to right-handed hitters, Santana's changeup is exactly average, with a regressed LWTS/pitch of 0. Last year, the swings and misses the pitch created were counterbalanced by the pounding the ball took when it was put in play. Against righties the pitch Santana was most effective with was his fastball, which was worth -.03 runs every time he threw it (it also fell just outside the top-10). There are a ton of factors that impact how effective a pitch is, and maybe right-handed batters have started to sit on Santana's changeup more at the expense of hitting his fastball, but for last year at least, his changeup was pedestrian while his fastball was tremendous.