Note: this was lifted almost verbatim from a thread at Brewerfan. But I lifted it from myself and my own research (research on a Friday night, no less), so I don’t feel bad about it.
The question: Is it possible for Zack Greinke to continue getting shelled while maintaining a high strikeout rate?
The answer: It’s possible, but very unlikely.
The why: I intended to compare Greinke’s strikeout rate with previous pitchers who finished the season with somewhere around his 11.8 K/9, but starting pitchers have recently quite rarely struck out that many batters. The last qualifying starting pitcher with even as much as an 11.0 K/9 was Kerry Wood in 2003 (11.35). The last starting pitcher to eclipse 11.8 over a full season was Randy Johnson in 2001, with a 13.41 K/9.
So instead of looking at trying to find a number of direct comparisons with Greinke, let’s look at MLB qualifying starting pitchers who finished in the top 5 in K/9 the last five years, along with their ERAs.
Tim Lincecum: 9.79 K/9, 3.43 ERA
Jon Lester: 9.74 K/9, 3.25 ERA
Yovani Gallardo: 9.73 K/9, 3.84 ERA
Jonathan Sanchez: 9.54 K/9, 3.07 ERA
Francisco Liriano: 9.44 K/9, 3.62 ERA
Tim Lincecum: 10.42 K/9, 2.48 ERA
Justin Verlander: 10.09 K/9, 3.45 ERA
Jon Lester: 9.96 K/9, 3.41 ERA
Yovani Gallardo: 9.89 K/9, 3.73 ERA
Javier Vasquez: 9.77 K/9, 2.87 ERA
Tim Lincecum: 10.51 K/9, 2.62 ERA
Edinson Volquez: 9.46 K/9, 3.21 ERA
A.J. Burnett: 9.39 K/9, 4.07 ERA
Chad Billingsley: 9.01 K/9, 3.14 ERA
CC Sabathia: 8.93 K/9, 2.70 ERA
Erik Bedard: 10.93 K/9, 3.16 ERA
Scott Kazmir: 10.41 K/9, 3.48 ERA
Jake Peavy: 9.67 K/9, 2.54 ERA
Johan Santana: 9.66 K/9, 3.33 ERA
A.J. Burnett: 9.56 K/9, 3.75 ERA
Jake Peavy: 9.56 K/9, 4.09 ERA
Johan Santana: 9.44 K/9, 2.77 ERA
Orlando Hernandez: 9.09 K/9, 4.66 ERA
Carlos Zambrano: 8.83 K/9, 3.41 ERA
Brett Myers: 8.59 K/9, 3.91 ERA
That’s a mean of 3.36 ERA, a midpoint of 3.41 ERA, a min of 2.48, and a max of 4.66.
Greinke’s ERA is currently 5.23. If Greinke finishes in the top 5 in K/9 (i.e., he keeps his strike out rate around or at a slightly lesser clip than he is doing now), it seems quite likely that his ERA would drop. How much? I dunno. But drop it probably would. And maybe a lot.
ZiPS has Greinke finishing with 167.2 IP, by the way. Pitchers need 162 IP to qualify for the above lists.