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fearofpopvol1
09-05-2011, 03:22 PM
Has he been overvalued in the field? Or did he just have an incredible 2010?

His 2008 wasn't inspiring, but he was a rookie. 2009 was very good, but it was half of what his 2010 was in terms of his URZ rating. 2011 though? He's been a negative defender.

2008 (108 games): -2.4
2009 (101 games): +9.2
2010 (148 games): +19.7
2011 (135 games): -0.5*

*2011 is obviously not finished yet

So who is the real Jay Bruce in the field?

RedsManRick
09-05-2011, 03:34 PM
Has he been overvalued in the field? Or did he just have an incredible 2010?

His 2008 wasn't inspiring, but he was a rookie. 2009 was very good, but it was half of what his 2010 was in terms of his URZ rating. 2011 though? He's been a negative defender.

2008 (108 games): -2.4
2009 (101 games): +9.2
2010 (148 games): +19.7
2011 (135 games): -0.5*

*2011 is obviously not finished yet

So who is the real Jay Bruce in the field?

He's the guy who did all of those things. Just like he's both the guy who destroyed the league in May and stunk in June. In relatively small samples, performance varies. And a year of defense is about the same as 200 PA of hitting. What's his "true fielding talent"? Probably something like the average of those, 5 to 10 runs above average.

Ron Madden
09-05-2011, 03:40 PM
I still believe that Jay Bruce will someday win a Gold Glove.

edabbs44
09-05-2011, 03:52 PM
Jay has been overrated by some, without a doubt. But it doesn't mean he isn't good.

Homer Bailey
09-05-2011, 07:55 PM
I think those numbers (at least, the last two seasons) have accurately portrayed his defensive performance. I don't think there is any doubt that he was much better in the field last year than he has been this year. Both my eyes, and the numbers tell me that.

Reds1
09-05-2011, 08:33 PM
probably less opportunities after his 2010 effort. They don't run on him as often so he doesn't show his arm. He hasn't been as well overall, but I'll take him over anyone we can throw out there in LF, but maybe a little overrated, but very solid.

edabbs44
09-06-2011, 07:04 AM
I think those numbers (at least, the last two seasons) have accurately portrayed his defensive performance. I don't think there is any doubt that he was much better in the field last year than he has been this year. Both my eyes, and the numbers tell me that.

So if you do believe that the huge difference is due to his actual play rather than randomness of the metric, what do you think caused his falling off the proverbial cliff?

edabbs44
09-06-2011, 07:12 AM
He's the guy who did all of those things. Just like he's both the guy who destroyed the league in May and stunk in June. In relatively small samples, performance varies. And a year of defense is about the same as 200 PA of hitting. What's his "true fielding talent"? Probably something like the average of those, 5 to 10 runs above average.

Disclaimer: I am not a fan of UZR, especially when used in certain ways. However, I do think it generally gets us in the vicinity of where we would like to be. Especially when used properly.

My question is this: We have almost 500 games over 4 seasons to have viewed and assessed Jay's defense and, in those 4 seasons, have seen just one where his UZR fell within that "true talent" band. At what point does his number settle in? Or will it? If performance varies enough to take 2 "wins" away from Jay in one season, shouldn't that be accounted for when throwing WAR around like it is the be all talent evaluation tool? Especially in one season samples?

jojo
09-06-2011, 07:23 AM
In 4100 defensive innings as a major leaguer, Jay Bruce has posted a UZR/150= 8.2.

For the purposes of WAR, I'm comfortable with the notion that he's a +8 run plus defender.

lollipopcurve
09-06-2011, 07:27 AM
The metric doesn't mean all that much. The guy's a good defender out there with a very good arm. Trying to quantify it/compare him to others just kind of obscures things.

edabbs44
09-06-2011, 07:35 AM
In 4100 defensive innings as a major leaguer, Jay Bruce has posted a UZR/150= 8.2.

For the purposes of WAR, I'm comfortable with the notion that he's a +8 run plus defender.

If he drops a +20 on us next year, how would you view his WAR for 2012? Would you give him credit for that number?

jojo
09-06-2011, 08:56 AM
If he drops a +20 on us next year, how would you view his WAR for 2012? Would you give him credit for that number?

Yes. I'm giving him credit for his UZR this year.

Your premise seems to be that since his UZR has fluctuated, it isn't an accurate estimate of his performance. That premise would be begging the question.

lollipopcurve
09-06-2011, 09:04 AM
Folks can correct me if I'm wrong, but isn't the appropriate sample size for UZR 3 full seasons? I seem to remember those in the know saying so....

nate
09-06-2011, 09:51 AM
In 4100 defensive innings as a major leaguer, Jay Bruce has posted a UZR/150= 8.2.

For the purposes of WAR, I'm comfortable with the notion that he's a +8 run plus defender.

Agreed. I came up with something like 7-8 runs. He hasn't looked as good out there (according to my WoiP) this year as he had the previous two but he's still good.

nate
09-06-2011, 09:52 AM
Folks can correct me if I'm wrong, but isn't the appropriate sample size for UZR 3 full seasons? I seem to remember those in the know saying so....

It's "as large as possible" but 3 full seasons is generally regarded as a good assessment.

Homer Bailey
09-06-2011, 02:03 PM
So if you do believe that the huge difference is due to his actual play rather than randomness of the metric, what do you think caused his falling off the proverbial cliff?

I think, from watching him over the last two seasons, that he saved a ton of runs for the Reds last year, and hasn't saved nearly as many this year, as well as costing the Reds some. I have no ability to calculate the actual amount of runs, so I rely on the metrics to a certain extent, and I think they are very fair.

I think Jay's true defensive talent is well represented with his UZR/150 over the last 3-4 years. I expect him to have a better year defensively next year than he had this year.

RedsManRick
09-06-2011, 05:10 PM
Regarding UZR sample size (and all sample sizes really), there's never a magic number at which something goes from meaningless to meaningful. It's just that as your sample gets bigger, your error bars get smaller.

Sabermetricians usually put the "good sample size" figure at the point where the observed sample becomes more predictive than league average. For UZR, that happens at around 3 seasons worth of data. If you're trying to estimate a player's using just 1 season of UZR, you best guess is something like 5 parts league average and 1 part observed performance -- or better yet, trust the scouts.

jojo
09-06-2011, 05:41 PM
Folks can correct me if I'm wrong, but isn't the appropriate sample size for UZR 3 full seasons? I seem to remember those in the know saying so....

If one really wants to be comfortable estimating a player's true talent level, roughly 3000 defensive innings (or approx 3 yrs) seems to be the appropriate threshold.

That's a different issue than simply asking what defensive value was provided over a season (i.e. given the distribution of chances, how did a player perform relative to his peers), which may or may not be repeatable oe reasonable to expect going forward.

camisadelgolf
09-07-2011, 04:20 AM
This is unrelated, but I didn't think it deserved a thread of its own. Has anyone else noticed that before turning 25, Jay Bruce walks slightly more often than Joey Votto did at the same age in the majors?

lollipopcurve
09-07-2011, 07:14 AM
That's a different issue than simply asking what defensive value was provided over a season (i.e. given the distribution of chances, how did a player perform relative to his peers), which may or may not be repeatable oe reasonable to expect going forward.

My take is that the metric captures so little of the quality of the chances in a small sample size that crediting the defensive value entirely to the fielder in that zone is a mistake.