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Contributed by Jonathan Hale
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Monday, 07 April 2008 |
By Jonathan HaleLast week, I showed how pitchers with great reputations, specifically winners of the Cy Young award, on average get about an extra inch of the strike zone given to them by the home plate umpire. So if the celebrities of the big leagues are given extra credit, are the nobodies given an especially hard time?
Let’s take a group of young guys who before the 2007 season were not huge prospects (or international stars like Dice-K), and had never pitched a full season. Not all of these guys are technically rookies, but here’s a pretty unheralded group of 10 pitchers coming into last season: Team Rookie
Matt Chico Paul Maholm Matt Belisle Brian Bannister John Maine Boof Bonzer Shaun Marcum Matt Albers Jason Hirsch Andrew Miller
Now here’s the same graphs we used on the group of Cy Young pitchers for these greenhorns. Remember, it’s the point where half of all pitches are being called strikes that we’re looking for:
And now for the width of the strike zone (taken from behind the plate):
Here is a summary of the data as compared to the rest of the league.
| Rookies
| Rest Of League
| Rookie Bias
| Left
| 11.70
| 12.23
| -0.53
| Right
| 10.09
| 10.19
| -0.10
| Top
| 40.14
| 40.19
| -0.05
| Bottom
| 19.46
| 19.68
| -0.20
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So a rookie’s strike zone is maybe a little smaller, but not much when compared to the rest of the league (some of which is getting the “Cy effect”).
Now we can debate how much a half inch on the inside edge of the plate really means, or how much error there is from one year to the next in this sort of thing when only looking at 10 pitches. But one thing is clear- the results don’t jump off the page as they did for the best pitchers in the league. Rookies may be the whipping boys for everyone else, but umpires tend to give them just as much credit as the rest of the league.
Maybe showing an effect that doesn’t exist is a little underwhelming, but isn’t that nice to know? Umpires are human and get stars in their eyes as much as the rest of us when a legend is on the mound- but they manage keep their objectivity and not pick on some poor scared kid out there. |
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Last Updated ( Monday, 21 April 2008 )
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