Printer-friendly

Contact Author

March 25, 2008

Doctoring The Numbers

Royals and Phillies

by Rany Jazayerli

Kansas City Royals

One of my favorite old-time columns from this humble website is this one, written by Michael Wolverton back in 2004, which completely opened my eyes to not just the absurdity of the unearned run, but how evaluating pitchers by ERA instead of by RA systematically underrated good pitchers. That's because, with few exceptions, pitchers who excel at preventing earned runs also excel at preventing unearned ones. (For more on the subject, here’s Michael’s follow-up piece.)

The biggest of those exceptions is the knuckleball pitcher, who by his very nature will allow large numbers of passed balls (or rather, will force his catcher to allow them). As passed balls count as errors, they lead to unearned runs. By contrast, if you were looking for a pitcher who did not surrender a lot of unearned runs, you’d want to find one that:

• Pitched well–-good pitchers surrender fewer unearned runs than bad pitchers.
• Was a fly-ball pitcher–-fly balls are less likely to turn into errors than groundballs.

The rest of this article is restricted to Baseball Prospectus Subscribers. Not a subscriber? Click here for more information on Baseball Prospectus subscriptions or use the buttons to the right to subscribe and get access to the best baseball content on the web.

Cancel anytime. That's a 33% savings over the monthly price! That's a 33% savings over the monthly price! Already a subscriber? Click here and use the blue login bar to log in.