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Clutch Hits - Tango's 11 points to think about --- to understand why we regress towards the mean (February 12, 2004)
Discussion ThreadPosted 4:02 p.m.,
February 12, 2004
(#7) -
Jesus Christ Himself
MGL, you do a lot of great work, but come on...
Of course, the above quote is completely wrong and virtually everything you said was completely right. The notion that there is a finite chance that Barry Bonds is not really that good and just got lucky for 10 or 20 years (you know what I mean) or that Rey Ordonez' is really a pretty good hitter and just got unlucky for 10 years or so, creates so much cognitive dissonance in most people's minds that no matter what anyone says, some people are just going to think that you are anywhere from somewhat wrong to completely nuts.
The point is not that cognitive dissonance arises from regressing these players to the mean. The point is that why should other players' performance lead us to conclude that Bonds' current stats are better than his true talent, and that Ordonez' current stats are worse than his true talent? The average of other players' performances should not influence how we value any particular player.
And it's not just a matter of Bonds and Ordonez. This type of regression is basically saying:
Every above-average player is overrated by their stats, and every below average player is underrated by their stats.
I'm sure you wouldn't endorse this statement, yet that is what the regression does!!!
Clutch Hits - Tango's 11 points to think about --- to understand why we regress towards the mean (February 12, 2004)
Posted 7:03 p.m.,
February 12, 2004
(#11) -
Jesus Christ Himself
I was also posting as 'Late to the party' in the other thread...
Tango, MGL, and AED: these last three posts are excellent. I completely understand where you are coming from. That doesn't mean that I'm totally convinced, but now I understand your theory and your method (almost) completely. The only problem that remains is with the following statement made by MGL and alluded to by others:
"Any player who has stats higher than the mean of whatever population they come from is overrated, on the average, and every player who has stats lower than that mean is underrated, on the average![italics added for emphasis]"
The "on the average" statement is what I have a problem with. Like I said, it works for the group, but is meaningless at the individual level. It does nothing to improve our knowledge about one particular player. In which case, I would prefer to believe that a player's career stats are a better estimate of true talent than his regressed stats are (with enough PAs of course).
You guys have certainly made an intelligent attempt to defend your point and I am still not 100% convinced. Maybe it's just me.
By the way - tango: I would love to see all data presented as such.