tag:blogger.com,1999:blog-608528753722196209.post133086539179685087..comments2024-01-26T13:08:26.506-08:00Comments on Cybermetrics: Do Pitchers Differ In Their Ability To Prevent HRs? (and does it persist over time?)Cyril Moronghttp://www.blogger.com/profile/07148864847009186694noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-608528753722196209.post-28104948770497245752009-07-11T16:14:35.801-07:002009-07-11T16:14:35.801-07:00Hey Cy,
Sorry for the delay in responding here.
W...Hey Cy,<br />Sorry for the delay in responding here.<br /><br />What we must remember when conducting any study on MLB players is that there is inherent, tremendous selection bias at play. We are dealing with human beings who are among the best in the world at playing baseball. While we know that pitchers have very little control over their BABIPs, if we were to drop Johan Santana into the middle of a little league season, I can guarantee you that he would post a BABIP well below average. The findings from today's MLB game that we analysts write about can only be assumed to be true for the years and subjects the studies are conducted upon.<br /><br />This is such an important consideration that we can't even generalize our results onto the minor leagues, much less play from 80 years ago. It's very possible that a pitcher like Tim Linecum's .250 BABIP at Double-A in 2006 was based on skill and not simply luck. If he was a major league caliber pitcher pitching to minor league caliber batters, the rules don't stay the same. The same is true for the game years and years ago.<br /><br />The suggestions you provide might answer the "why" question, and as a fantasy analyst I really can't offer any other suggestions. I've never studied (or really even read anything about) anything other than the present, but it's very possible that game was simply different then and so the statistical rules are different. <br /><br />As to your second point, you're correct in that the more observations of something we have, the more we can say about a player's true talent level for that particular skill. If we were creating a projection system for Ks and HRs, there would be a much heavier regression to the mean component for HRs because we have less information about the pitcher's HR ability than for Ks. Adding more years would decrease the regression to the mean component, but there would be a natural one introduced because most pitchers regress to the mean over time.Derek Cartyhttps://www.blogger.com/profile/15051667211745800764noreply@blogger.comtag:blogger.com,1999:blog-608528753722196209.post-6182570179594286452009-07-05T18:54:03.391-07:002009-07-05T18:54:03.391-07:00Dang, that was fast, Derek. Thanks for commenting....Dang, that was fast, Derek. Thanks for commenting. Any thoughts on why the HR correlations were so low in those early years I looked at? That has me puzzled. Maybe HR hitting was new and pitchers had not figured it out yet? Maybe they were still such rare events that you would not see much correlation.<br /><br />I also wonder if I got a fairly high correlation for the 2 three-year periods because HRs are still such a rare occurrence (compared to walks and strikeouts) that it takes more observations to get a good read on pitchers. Is there anyway you could look at the HR/flyball rate for 2 three-year periods?<br /><br />Also, maybe we need to see a guy pitch 3-4 years before we know his "true" HR rate.Cyril Moronghttps://www.blogger.com/profile/07148864847009186694noreply@blogger.comtag:blogger.com,1999:blog-608528753722196209.post-28986504557396668752009-07-05T18:43:42.661-07:002009-07-05T18:43:42.661-07:00You hit the nail on the head, Cy: "This seems...You hit the nail on the head, Cy: "This seems high enough to say that, yes, pitchers do differ in the HR rates they allow, even if the reason is their flyball rates." Pitchers do differ in their ability to prevent HRs, but this is due to their ability to greatly control their fly ball rates. If you were to look at year-to-year correlations of HR/FB, they would be very low. As I noted in the original article, this applies only to SPs with a few exceptions. Some RPs follow the rule as well, but there are more likely to be exceptions here.<br /><br />Nice work :)<br /><br />-Derek CartyDerek Cartyhttps://www.blogger.com/profile/15051667211745800764noreply@blogger.com