Thanks for tying this discussion up a little, Fris, and FWIW, I never mind playing Charlie McCarthy to your Edgar Bergen ...
I've been wicked busy and haven't done anything more in this thread, but frankly, I kind of lost myself in this discussion. The main problem is that I really don't know all there is to the calculation of the new UZR so it's hard to get a good reference point for this discussion.
I understand the .8 run calculation as an approximation of run values of misplays over the average fielder, but there are two essential points I tried to make:
1. That value does vary widely according to zone. I do not know if they use varying run values according to which zone the misplay was in, but I hope they do.
2. That .8 run value is valid only when comparing players to "league average," using the .3 out value to zeroize the numbers. I understand this, but would also welcome some calculations and studies at the cumulative level (using the .11 out value) to get a feel for exactly how many runs players give up over the course of a year. This to me would be sort of a grand sanity check, because we know very well how nearly all other runs against are calculated, and if these numbers fit nicely into the overall model of cumulative team and league runscoring, then I think we would surely know how accurate they are.
Here is what that looks like, btw, using the 1992 Cincinnati Reds as an example:
Batting runs allowed: 832.6 runs As the lwts value of all hits given up
Residual runs allowed: 158.0 runs As the lwts value of all BB, HBP, SB, CS, WP, BK given up
Defensive out value: -426.0 runs As the lwts value of all outs made (using -.11 per out)
Defensive runs allowed: 46.2 runs As the lwts value of all errors made.
Theoretical runs allowed: 610.7 runs Total runs allocated by lwts measurements of the above
Actual runs allowed: 609.0 runs Actual runs allowed.
Lest you think I cherry-picked a team whose theoretical and actual runs are nearly equal, I should say that this model normally comes within +/- 10 runs.
Now where do the UZR runs fit into this model? Well, they don't on their own, because the values of everything else add up to within 10 runs of zero. So fielding runs would modify batting runs against and defensive out values to one extent or another. I would certainly like to know how much, but at the team level a single is a single, an out is an out, and it doesn't matter who the "blame" is assigned to.
I can, of course, break these numbers down to individual pitchers, using the top three categories to measure pitching performance, and calculate their performance on a per BF (or per 27 outs if you prefer) level, which is very useful.
Perhaps the most wonderful thing we could gain from being able to isolate the effect of team defense in terms of cumulative runs would be to modify pitching performances to be truly defensive-independent.
Anyway, as I develop a larger set of data, it may be possible to perform correlations of this data against things like RF, or DERA or other non-quite related measurements to see if there is a relationship, especially with the outlier teams.
So anyway, back to the numbers listed in the model, I would like to know how many plus and minus plays UZR assigns per team, per season. If anyone knows where I can get that data, I can do a quick check against the above data for a sanity check.
Edited by Vermonter At Large, 25 March 2007 - 09:57 AM.