|12-07-2012, 04:07 PM||#1|
Join Date: Oct 2000
An alternative method for determining defensive WAR
|12-07-2012, 07:38 PM||#2|
Stat Wanker Hodiernus
Join Date: Dec 2004
Location: Chicago, IL
Re: An alternative method for determining defensive WAR
The one thing I've never understood is why the variance in WAR from year to year is almost always treated as evidence that it is unreliable as a measure of performance for that year.
Sure, the small sample issue means it is not a good measure of talent. But talent and performance are not synonymous. If we looked at offensive stats after 200 PA, we'd see many more odd peaks and valleys. But we wouldn't say they're an unreliable measure of offensive production over those 200 PA.
Now, I realize a big part of the issue with Barney is the difference between UZR and DRS -- I'm very curious about that too. But how prevalent are those types of gaps. I decided to check it out:
A total of 123 players had the number of innings to "qualify" per Fangraphs. The distribution of the variance between UZR and DRS looks like this:
(UZR higher than DRS)
+10 and up: 6
+5 to 10: 12
+2 to +5: 24
-2 to +2: 34
-2 to -5: 22
-5 to -10: 18
-10 and down: 7
I find that interesting -- it's a pretty normal distribution. That suggests that whatever the difference is, it cuts equally both ways. I also looked by position and it doesn't seem to be biased towards or against a certain position. The R-squared between the two for that population is 0.69, a fairly strong positive, but nothing like you'd hope for given that they're supposed to be measuring the same thing.
Looks like there's definitely a reason to be skeptical about the numbers -- but I'd rather get an actual explanation looking at how they coded/valued things differently and choose the approach that seems more correct than simply average them.
Games are won on run differential -- scoring more than your opponent. Runs are runs, scored or prevented they all count the same. Worry about scoring more and allowing fewer, not which positions contribute to which side of the equation or how "consistent" you are at your current level of performance.