Does the stretch cost a pitcher fastball speed?by Mike Fast
April 20, 2010
Earlier today, Rob Neyer wrote about Ubaldo Jimenez's no-hitter at his Sweet Spot blog at ESPN. He linked to an article by Thomas Harding about Jimenez's switch of pitching deliveries mid-game:
It was after the fifth-inning leadoff walk that Apodaca mentioned the idea that saved the game and set up Jimenez for history.That's certainly fascinating to me, but what struck a researcher's nerve with me was Rob's comment about this all:
At the start of innings, Jimenez, like every starting pitcher, was throwing with a full windup. Throughout his career, Jimenez has been far more effective from the windup than from the stretch, the side-to-the-plate stance pitchers use with men on base. But Saturday, he was more effective from the stretch. That meant less of a leg kick and, on Saturday, more control of his body.
"I talked to him between innings and he said he just felt lost," Apodaca said. "To me, it was night and day the way he was executing pitches. His timing, as far as getting the ball out of his glove, and his delivery to the plate were all sharper out of the stretch.
It's often said that the stretch costs a pitcher 2-3 miles an hour off his fastball, and (considering how easy that is to check) I'll assume that's roughly accurate.It is very easy to check, and it turns out that it's not accurate at all. A pitcher's fastball speed turns out to be almost identical with runners on base as compared to his average fastball speed with the bases empty. If anything, the average starting pitcher throws about 0.1 mph harder with runners on base.
Of course it could be that a typical pitcher bears down more and tries to throw harder when there are men on base in order to get the batter out and keep them from scoring. But if pitching from the stretch was a significant hindrance to fastball speed, you'd think we'd see it reflected in the data anyway, even if the pitcher was trying to throw harder. I doubt that the baseball adage that Rob mentioned was merely saying that pitchers end up throwing the same speed from the stretch as from the windup because they're trying harder.
I realize that runners on base vs. bases empty does not correspond exactly to pitching from the stretch vs. the windup for every pitcher, but it should be close to enough to reveal any major differences between the two. I looked at the time period 2008-2009, first at all pitchers who had thrown at least 1000 fastballs, which would include quite a few relievers, and then those pitchers who had thrown at least 2000 fastballs, which should be mostly starting pitchers. The results were not markedly different between the two groups.
What about Jimenez in particular? He has averaged 95.7 mph with the bases empty and 95.6 mph with runners on base.
The two starting pitchers who really crank it up with men on base? That's Justin Verlander--94.1 mph with the bases empty and 95.4 mph with runners on--and Ted Lilly--86.2 mph with bases empty and 87.7 mph with runners on. And a virtual cookie (your favorite kind, of course) to the first person who can pick out Jamie Moyer's dot on that chart.
Mike Fast is a Royals fan who enjoys investigating baseball questions using data of many sorts. He is a member of Complete Game Consulting. He welcomes comments via e-mail.