Clayton Kershaw’s Effect on the Dodgers Bullpen
Ken Rosenthal has an NL MVP vote this year, and the other day, he wrote about his thought process in regards to pitchers winning the award. He’d prefer to vote for a position player, but isn’t entirely against pitchers-as-MVPs, and he noted that a dominant starter who works deep into games doesn’t just affect the team on the day they pitch, as is commonly cited. Quoting from his column:
The one pro-Kershaw argument I do like – the one I recall making for Pedro Martinez in 1999 and 2000 – is that a dominant starting pitcher affects three games out of five. Kershaw averages more than 7 1/3 innings per start. Dodgers manager Don Mattingly can empty his bullpen the day before Kershaw pitches and manage a fully rested group the day after.
This does seem to be a potentially real benefit created by Kershaw that is not being accounted for anywhere in his own stat-line. While there is a lot of talk about players “making their teammates better”, this would be one actual place where it could exist, with a starting pitcher allowing his manager to reallocate his bullpen usage to the days around Kershaw, increasing their chances of winning on those days as well. This is the kind of thing that we wouldn’t capture by just looking at Kershaw’s performance.
But is it true? Rob Neyer was smart enough to realize that we should be able to find some data to test this theory, and so I bugged Jeff Zimmerman about it, and he was nice enough to query out the Dodgers’ bullpen usage on days before and after Kershaw pitched this season. Here are the results.