Want to see an example of what effect Coors Field might have on pitchers' stats?
This is, I a admit, totally anecdotal and a sample size of 1 which is absurd, but still, this is interesting.
Doing research for a progressive team I stumbled on Mike Hampton's ERA numbers. Here they are:
1995 Houston 3.35
1996 Houston 3.59
1997 Houston 3.83
1998 Houston 3.36
1999 Houston 2.90
2000 NY Mets 3.14
2001 Colorado 5.41
2002 Colorado 6.16
Each of these seasons he pitched between 170 and 240 IP
Maybe he just got old you say ? Good question. When I teach (mostly qualitative - alas if it were quantitative I would have won a championship here already !) research methods I always teach that to find causality the MINIMUM criteria we must establish are:
1. (hypothesized) Cause must come before effect - (this is not quantum physics, but social science, where quantum non-locality does not apply) - in this case his shift to Coors came before his ERA ballooned, so so far we have validity.
2. there must be a plausible relationship between cause and effect (the example I always give is that the NY Yankees, since 1960 have only won World Series in years in which a Democrat has been in the White House (look it up, it holds). But there is no plausible relationship between the two facts, so it is coincidence. In Italy, by the way, everyone would say "A-Ha ! See it's all fixed by the politicians" since most soccer teams are owned by politically active wealthy people, the most prominent being only recently ex-prime minister Silvio Berlusconi owner of Milan. But since the late G.Steinbrenner was a well-known Republican (he got in trouble at one point for having made illegal donations to Nixon), it doesn't work like that here. But since there could be a relationship (common sense here) between baseball parks and pitchers' ERAs, without knowing that there is one, we have plausibility so we can continue.
3. We must exclude or account for other possible explanations - that is other potential causes of the effect we see - as in the question about whether Hampton was just over the hill (or the Rockies as it were). Since I teach social sciences and not science sciences, there is no such thing as a "proof" - a mathematical term. Only "what is the best explanation with the weight of the evidence on its side among the plausible contending explanations." Was he over the hill?
2003 Atlanta 3.84
2004 Atlanta 4.28 - here we might find that in a year 0.44 - all other things being equal, was the aging effect, not 2.00+ as in when he pitched in Coors
After that he never gets close to 170 IP again, but in 2005 with 70 IP at Atlanta his ERA was 2005. Doesn't prove it was Coors, but it is some incriminating evidence if I have ever seen any - more than 2 full points on the ERA compared with other parks.
By the way, if you have never been there, Coors field is lovely - a very relaxing park to watch baseball in. My sister lives in Denver so I have been there many times. Wouldn't want to pitch there though. Coors beer on the other hand is horrible. Jimmy the Red, the legendary owner of the great Greenwich Village (NY) bar Googies, once was offered a free sample keg of Coors, which he didn't have on tap, and he rolled it out onto West 3rd street, took an ax to it and dumped beer all over the sidewalk.
So ends our Research Methods lesson for today. That'll be $45,000.
6/7/2012 8:36 AM (edited)