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Lincecum’s Great Changeup

Last night Tim Lincecum was the youngest pitcher to start an all-star game since Dwight Gooden. Lincecum is having a great year, striking out over 10.5 batter per nine, with, having cut his walk rate for the third year in a row, a K/BB over four. He is best known for his electric fastball, but interestingly this year he is throwing it a bit less (59% of the time versus 66% of the time in 2008 and 2007) and the average speed has dropped from 94 mph to 92.5 mph. It looks like Lincecum is learning to take a little off the fastball and mix in his curve and changeup more often.

His curveball is quite good, worth about one run per 100 pitches over the past three years. It is has lots vertical movement-12 to 6 break-and induces nearly a 30% whiff rate. He throws it about equally to lefties and righties, about 16% of the time.

His changeup is a great pitch. He throws it more to lefties (24% of the time), but still throws it to righties fairly often (16%) a testament to how good it is. The pitch has been worth 5.28 runs per 100 pitches this year, which is just incredible. Of pitchers who have thrown more than a handful of changes the next closest is Josh Johnson‘s worth 3.8 runs per 100. Among starting pitcher’s changeups it is second to only Rich Harden‘s in whiff rate. It is a huge reason for his success.

Of course you cannot evaluate his changeup in a vacuum, since its success is predicated on his fastball. Here is the average run value, change in run expectancy, of changeup based on the number of fastballs that preceded it in an at-bat. The numbers are averaged over his career not just 2009.

| Num. Preceding FB |  Run Val of CH |
| 0                 |         -0.014 |  
| 1                 |         -0.026 |
| 2                 |         -0.028 |
| 3                 |         -0.023 |
| 4+                |         -0.010 |

After the first fastball the success almost doubles, where it stays until, as the at-bat lengthens, it falls back off. The two pitches average about 9 mph difference in speed. Here is the change in run value for his changeup based on its difference in speed from the previous fastball. The gray lines are error bars.


As you can see the success of Lincecum’s changeup is very much influenced by his fastball. When he is throwing it 8 to 10 mph slower than his fastball (as he does on average) he is successful. When it gets too slow or too fast, he is not as successful.

Changeups have no platoon split and as with other pitchers who succeed on the strength of a great changeup Lincecum shows almost no platoon split. It will be fun to continue to watch the career of this great young pitcher getting it done with a superlative changeup-fastball combo.