The Sub-2.50 ERA Curse: Why Hernandez, Halladay, Buchholz, Johnson & Wainwright May Regress in 2011
Tue, Jan 4, 2011 by Nick Kappel
Last March, I conducted a study on pitchers who’ve posted a single-season ERA of 2.50 or less since 2000. (You can read that article here.)
In my research, I made several interesting discoveries. First, there were 11 different sub-2.50 ERA seasons between 2000 and 2005. Between 2006 and 2008, however, there were none.
2009 saw four such pitching performances, as Zack Greinke (2.16), Chris Carpenter (2.24), Tim Lincecum (2.48), and Felix Hernandez (2.49) all posted ERAs below 2.50.
This recent trend supports the notion that hitters are no longer juicing, and thus pitchers are becoming more dominant. (Keep this in mind as you prepare for your 2011 fantasy drafts.)
Second, I found that of the 11 instances of a sub-2.50 ERA season, nine of them were followed up with a significantly higher ERA in the following season. In fact, on average, each pitcher’s ERA increased by 1.01 runs per nine innings in the season following their sub-2.50 campaign.
Here’s the list. The second column shows the year in which the pitcher’s sub-2.50 ERA was posted. Column four reveals the difference in ERA for the following season.
| PLAYER | YEAR | ERA | ERA DIFF. |
| Roger Clemens | 2005 | 1.87 | (+0.43) |
| Andy Pettitte | 2005 | 2.39 | (+1.81) |
| Jake Peavy | 2004 | 2.27 | (+0.61) |
| Pedro Martinez | 2003 | 2.22 | (+1.68) |
| Jason Schmidt | 2003 | 2.34 | (+0.86) |
| Kevin Brown | 2003 | 2.39 | (+1.70) |
| Mark Prior | 2003 | 2.43 | (+1.59) |
| Pedro Martinez | 2002 | 2.26 | (-.04) |
| Randy Johnson | 2002 | 2.32 | (+1.94) |
| Randy Johnson | 2001 | 2.49 | (-0.17) |
| Pedro Martinez | 2000 | 1.74 | (+0.65) |
Based on these numbers, I predicted the 2010 ERA totals for the four pitchers who posted a sub-2.50 ERA in 2009:
| PLAYER | 2009 ERA | 2010 ERA PREDICTION | 2010 ACTUAL ERA |
| Zack Greinke | 2.16 | 3.17 | 4.17 |
| Chris Carpenter | 2.24 | 3.25 | 3.22 |
| Tim Lincecum | 2.48 | 3.49 | 3.43 |
| Felix Hernandez | 2.49 | 3.5 | 2.27 |
Greinke’s ERA ballooned by more than two runs per nine. Carpenter’s and Lincecum’s ERA rose by approximately a full run per nine, just as the previous data suggested.
Hernandez completely blew up the system, becoming just the third pitcher since 2000 to lower his ERA following a sub-2.50 ERA season. The other two to do this were Randy Johnson and Pedro Martinez, who lowered their ERA by .17 and .04, respectively. King Felix managed to lower his ERA by .22.
If we include the data from 2009-2010 with our previous findings, we should apply an increase of 0.99 runs per nine innings to any sub-2.50 ERA seasons from 2010.
Five pitchers posted a sub-2.50 ERA in 2010: Felix Hernandez (2.27), Josh Johnson (2.30), Clay Buchholz (2.33), Adam Wainwright (2.42), and Roy Halladay (2.44).
Plug in our +0.99 runs per nine to those totals, and we get the following 2011 ERA totals: Felix Hernandez (3.26), Josh Johnson (3.29), Clay Buchholz (3.32), Adam Wainwright (3.41), and Roy Halladay (3.43).
Although these ERAs remain respectable, they are a far cry from what most owners are expecting in 2011.
You’ve been warned…again.
Image courtesy of: Mark Sobba
Previous articles from Fantasy Baseball Insiders:
- 2010 Batting Average on Balls in Play Leaders: What to Expect in 2011?
- 2011 Closer’s Corner: Papelbon, Cordero & Rivera Are the Only Reliable Options
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Tags: Adam Wainwright, Andy Pettitte, Chris Carpenter, Clay Buchholz, Felix Hernandez, Jake Peavy, Jason Schmidt, Josh Johnson, Kevin Brown, Mark Prior, Pedro Martinez, Randy Johnson, Roger Clemens, Roy Halladay, Tim Lincecum, Zack Greinke
Hey Nick, good to see you back! Very interesting article. It makes you wonder what the cause is, like are they still fatigued from overexerting themselves the year before or were they just the beneficiaries of a few extra good bounces that dropped their ERAs so low. I bet the answer is in their FIPs or tERAs but I haven’t looked.
Really weak
Someone who discusses this topic without mentioning “regression to the mean,” is displaying a lack of statistical knowledge. Yes, we can expect any pitcher who has an extraordinary season to retreat to an ERA closer to his “mean” performance. But you need to determine what that pitcher’s own mean is, not the mean of a collection of pitchers.
The results of this study are obviously based on regression to the mean. I’m not suggesting that the pitchers above will have ERAs exactly .99 runs above their 2010 total, but history suggests an average regression would lead to that.
Realistically, I’d expect one of those pitchers to completely flop this season, one of them to shine, and the other three to regress in a way that the numbers suggest.