from Amazon
Wednesday, August 19, 2009
Is UZR limited because the baseline is zeroed-out to that year’s average?
Jeff thinks so:
As you can see Mr. Cabrera’s UZR value jumped by 22 points in 2005 and in 2006 it went down to 2004 levels. Want to guess what the other shortstops UZR values did in 2005. Take a look at a chart of the drop off. As it can be seen in 2006 when Cabrera’s numbers lowered, everyone else’s UZR values adjusted up close to about what they previously were at.
That’s a nice way to show it. When you zero-out the hitting stats, you’ve got 200 or 400 players (depending whether you separate by AL/NL or not) that you are comparing players to. But with fielding stats, you are zero-ing out at the position level, and therefore, severely shrink the pool. Seeing how fluid players are (today’s SS is tomorrow’s 2B, etc), that’s not a good thing.
Jeff notes that maybe we can use the Fans’ Scouting Report. I agree. And, I have done that in the past. Indeed, you can look at the average RF and LF using the Fans’ and you will see that there was an enormous gap last year in the average player at each of those two positions. Traditionally, the average UZR of players moving from one position to the other has been fairly even, suggesting that the average at each position is equal. This is definitely not the case as of last year.
Theoretically, someone like Carl Crawford “improves” each year because while he keeps being used in LF, worse and worse outfielders are finding a home in LF. It’s like a park factors for Fenway dropping, as more and more hitter-friendly parks are introduced. The Fans Scouting Report does away with all that, and set the average baseline as “50” without consideration of position. You can then look at the average at each position to see how much talent has moved in or out of that position for that year.