March 9, 2015

BP Unfiltered

A Kershaw Day fun fact

by Zachary Levine

Are you enjoying your Clayton Kershaw Day? We’re glad we can play a small part in spreading the awareness that he’s good at baseball.

Anyhow, there’s one more way to mention in which he’s probably even better than he looks to the naked eye, and it doubles as my new favorite Clayton Kershaw fun fact.

Fun fact: Since Petco Park opened in 2004, no non-Rockies/non-Padres pitcher has a bigger difference of starts at Coors Field minus starts at Petco Park than Clayton Kershaw.

Nobody who pitches in Dodger Stadium should get all that much sympathy, but thanks to the unkindness of the schedule, Kershaw has started 15 games at Coors Field and only nine at Petco Park in his 6 2/3-year career. He’s never started three times in a season at Petco and didn’t start there at all last year.

The unlucky list, from 2004-present:

Pitcher	Coors	Petco	Difference
Clayton Kershaw	15	9	6
Paul Maholm	7	2	5
Wandy Rodriguez	8	3	5
Tony Armas	4	0	4
Brett Myers	6	2	4

Conveniently, the Kershaw fun fact itself doubles as a Felix Hernandez fun fact. Thanks to the Mariners’ and Padres’ “natural rivalry,” no pitcher has benefited from Coors/Petco schedule luck more than Hernandez.

Pitcher	Coors	Petco	Difference
Felix Hernandez	0	7	-7
Chad Billingsley	7	13	-6
Javier Vazquez	0	5	-5
Carlos Zambrano	1	5	-4
Cole Hamels	4	8	-4
Wade Miley	4	8	-4

The second name on the Petco-heavy list might have something to do with Kershaw’s number. The Dodgers’ mid-rotation mainstay was chillingly bad in his seven starts and one relief appearance at Coors, putting together a 7.26 ERA. However, Billingsley started three times there in 2011, and in 2012, when the trend was becoming clear, there was no sign of manipulation around either of the first two series at Coors. He was shut down right before the third one, and Kershaw didn’t pitch that one.

So it appears to be just luck, and for Kershaw, it hasn’t been good luck. To be less than delicate with the math, take 20 innings from Coors to Petco and given park factors, he’s down about three runs or from 2.48 lifetime to 2.46. Make the change at Kershaw’s own ERA gap (4.58 Coors vs. 2.22 Petco), and it’s down a couple more points.

Of course, this is why we have park factors and ballpark adjusted measures like FRA and ERA+. But Kershaw is probably owed a few starts in the marine layer if the game ever decides to be good to him.

Zachary Levine is an author of Baseball Prospectus. Follow @zacharylevine
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