Clayton Kershaw at Reduced Velocity?

Yesterday, I ran out of time while writing my MASH Report to look at how the possible effects of diminished velocity could have on Clayton Kershaw. Well, using a couple of untested, but promising ideas, it seems he will be may not struggle with less fastball speed.

The worries with Kershaw stem from this tweet.

He could be getting some of his strength back, but a possible 2+ mph drop could mean trouble for him. Kershaw’s fastball has at least averaged 92.5 mph in each of his six previous season. By looking at how he has produced previously at times with a lower velocities my indicate how he will do in the future.

For the first method, I will look at the games in which Kershaw averaged different fastball speeds and his performance. Carson Cistulli used this method to look at the decline of Ubaldo Jimenez as his velocity dropped. Here are Kershaw’s results when his games are group by fastball velocity.

Velocity K% BB%
<92 25% 6%
92.1 to 93 25% 8%
93.1 to 94 26% 8%
94.1 to 95 26% 11%
>95.1 24% 8%

Looking at the various values, Kershaw didn’t see any production decline with a slower fastball. Jimenez on the other hand, saw his xFIP increase from around 3.2 to 5.5 with Kershaw’s xFIP pretty much staying right around 3.50.

The problem with the above method, the average velocities only have a limited range. I am putting the final touches on a piece for the Hardball Times where I look at run values for a pitcher’s fastball. I group the fastball’s results by velocity. With this information, we may be able to determine at what velocity a pitcher will see a drop in performance. For example, Felix Hernandez has lost 4mph from his fastball since joining the league, but is still pitching at a similar level of production. The before mentioned Ubaldo Jimenez has seen about the same drop in velocity and is not close to being the same pitcher.

Here is the average per pitch run values (negative values are good for pitchers and positive value are bad for them) for Kershaw and Jimenez at different velocities:

Note: I wanted to be able to look at situations where a pitcher has a velocity change and the possible result change. While the details are the process are thin … have some patience. In a week or so, I will go into way too much detail on this subject for The Hardball Times. Until then, you will need to trust me on the process.


Again, nothing but consistency for Kershaw at lower velocities.

From what I can tell, a small drop in velocity will probably not hurt Kershaw’s production. I can’t be 100% sure of no decline, but at lower fastball speeds, he has produced efficiently in the past.

Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won three FSWA Awards including on for his MASH series. In his first two seasons in Tout Wars, he's won the H2H league and mixed auction league. Follow him on Twitter @jeffwzimmerman.

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Francis C
Francis C

Good to know. Maybe the reduced velocity is an opportunity to scare a Kershaw owner into trading him away.