Scott wrote:
Any measure that suggests Jack Morris = Jamie Moyer is seriously flawed.The measure in question is Adjusted ERA. As the linked article says, Adjusted ERA measures how much better or worse than league average a pitcher is or was within the context of that season. It also attempts to take ballpark effects into consideration.
The statistic does not lie. Moyer's ERA is five percent better than the average pitcher's across his career while Morris is also five percent better.
If Scott's point is that Adjusted ERA doesn't tell us everything we need to know about a pitcher, I'm inclined to agree. The biggest problem with the statistic, of course, is that ERA is an inherently flawed metric in measuring how effective a pitcher is.
However, the statistic itself doesn't lie. Jack Morris' 3.90 ERA was five percent better than league average over the course of his career, while Jamie Moyer's 4.22 ERA is five percent better over the course of his career.
One argument that can be made against Career Adjusted ERA is that it can diminish what certain pitchers accomplished. Greg Maddux put up adjusted ERAs from 2003-2008 of 108, 109, 104, 109, 98, and 93. In other words, he was a slightly above league average or below league average pitcher in the twilight of his career. This makes his career Adjusted ERA of 132 that much more impressive.
To ameliorate this phenomenon, we can look at a pitcher's five best Adjusted ERA seasons to see how dominant he was during his peak. What does this tell us about Morris and Moyer?
Jack Morris
1979: 133
1986: 127
1987: 126
1991: 124
1981: 124
Jamie Moyer
2003: 132
1999: 130
1998: 130
1993: 130
2002: 128
It doesn't change much. Neither Morris nor Moyer had any particularly dominant seasons.
Are Morris and Moyer the same pitcher? No. I'm inclined to agree with Scott that Morris was better, but the numbers definitively challenge this notion.
1 comment:
Mike, thanks for the additional analysis. My initial comment was more "message board material", and not in keeping with the insightful and detailed discussion you have established in your wonderful blog.
Even before your latest post, the debate did cause me to go look at Morris's and Moyer's career stats. Quite frankly I was surprised by Moyer's accomplishments during his prime.
One big difference I noticed was the number of CGs turned in by Morris in his best years. He was a hoss.
Also, I had forgotten how pedestrian Morris became in his later years.
Keep up the good work!
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