The Best Pitch of 2009
Everyone loves end of the season superlatives, so I thought I would join the fun and present 2009's best pitch. First let me say that this is a shameless rip-off of John Walsh's original 'Searching for the game's best pitch' when he looked at the 2007 season's best. I use Walsh's metric which values each pitch by the change in run expectancy from before and after the pitch. Walsh came up with the idea and describes it in that article, it is the way I have always done it and is the way FanGraphs values pitches. The caveat is that it is not stripped of the influence of ballpark, defense or luck. Harry Pavlidis has addressed that with his Expected Run Value, but here I am sticking with the original.
Another way to look at and value pitches is as Chris Moore and Jeremy Greenhouse have done here at Baseball Analysts looking at the process rather than the results. They value fastballs by their expected value based on movement, speed and location. But, again, I am going to go 'old fashioned' and just go with change in expectancy.
A second thing to note is that the owner of the best pitch of 2009 was in the news yesterday for something other than having the best pitch in baseball. I didn't notice until reading it over at Shysterball this morning. The timing is purely conicidental, my only hope is that this news will provide the pitcher a degree of solace if he is feeling down about the recent events.
Anyway, the best pitch of 2009 is Tim Lincecum's changeup. By FanGraphs' reckoning it reduced the run expectancy of Giant's opponents by 35 runs, no other single pitch was above 30 runs. On a rate basis (per pitch) it is the best for any pitch thrown over 200 times. I get the similar results (different numbers but Lincecum's change still comes out on top) when I run it with my pitch classifications and run values (FanGraphs goes with the BIS pitch identifications).
With each year since his debut Lincecum has thrown fewer fastballs, thrown them slower and thrown more changeups. It looks like he is really getting more comfortable throwing other pitches and taking a little bit off his fastball. In 2009 he threw the changeup 13% of the time to RHBs and 26% of the time to LHBs. It is nine mph slower than his fastball.
Here are Lincecum's pitches based on their spin deflection (Mike Fast has told me this is a better term for pfx_x and pfx_z than horizontal movement and vertical movement).
Here is how that looks in regards to where the pitch ends up.
A big reason for the pitch's success is its whiff rate, that is the percentage of time that a batter misses it when he swings at it. Lincecums' changeup has a whiff rate of 43%, while the average change just 28%. The rate at which batters swing at his change and whiff when they do swing is highly dependent on the height of the pitch. Here are those rates for Lincecum's change (orange) and the average change (gray).
In the middle of the season I checked in on Lincecum's chanegup over at FanGraphs and noted that its value was dependent on its speed differential from the preceding fastball and the number of fastballs preceding it in the at-bat. So we cannot say that Lincecum's changeup succeeds in a vacuum; its success is predicated on his fastball. That is one of the limitations of this pitch valuation system. Another is that Lincecum gets credit for the Giants excellent defense, pitching in the NL and pitching half his game in a pitcher's park.
With those caveats in mind, there you have it Tim Lincecum's changeup, 2009's best pitch.