Otto von Ballpark

It is tough to respond to this because I didn't call Hunter the worst outfielder in baseball. If someone does and cites UZR as proof, then that person is obviously misusing/misapplying it. I still don't understand what you want UZR, or people who reasonably consider UZR as one of several inputs for their evaluations, to do about it.

That still assumes Gutierrez converted notably more nonroutine plays into outs in 2009 than 2010. It might very well be due to sample and opportunity, but I still think it is interesting to know. Maybe more years of this data would suggest which year was more the outlier.

It is not that big or impossible. I don't have the exact number handy, but it is less than a run. Maybe 0.7 runs for a hit to the outfield? And the fielder only gets debited that full amount from his UZR if the average player at his position coverted it into an out at virtually 100% rate. That's not why Gutierrez went from +30 to 0 UZR. He would have needed to miss 40 such balls in 2010 over 2009 for that to be true.

That is an argument for defensive WPA Win Probability Added. A diving catch with the bases loaded and two outs is more valuable than an identical catch with no one on. Interesting, but not really a good way to estimate fielding performance or ability.

Is this assuming that zero balls are hit anywhere else to LF or left center? Such plays at least occasionally converted into outs by the average LF but not converted into outs by Arcia would negatively affect his UZR, probably offsetting the cans of corn and then some. But yes, if every ball hit to left or left center is coverted into an out by Arcia, he will have a positive UZR, as it should be.

Where don't I see a need for change? I welcome our FieldFX overlords. I hope they tweak UZR as they can, and provide more detail about its calculation. Those would be awesome things. I'm not deriding anyone for lack of understanding. Admittedly I probably am deriding folks for not so thinly veiled hostility to the idea of present-day run estimators... If you see an outlier, it's OK to say it's an outlier. I get a little testy when instead an outlier is called "absurd" and suggested (or flatly stated, Chief ) that the metric is thus untrustworthy. And I really roll my eyes when it leads to "that's the problem with these SABR types." Let's honestly ask: how big a part of the game is defense? And discuss. Without preconceived notions of how bad current metrics are at helping answer the question.

If anyone reads an article about stats such as "wins above average/replacement" or "runs about average/replacement", which are by name and definition theoretical constructs and quite obviously not anything that exists on a baseball scorecard, and assumes they are perfect or precise or immediately corroborated by the simple records on said scorecard, is demonstrating some level of preconceived hostility to the endeavor, I think. Perhaps borne out of honest skepticism, but still, that's just as much an issue with the reader as the author. If you are looking for an admission that defensive estimates are harder to calculate and predict than offensive estimates, I've seen plenty of such statements at Fangraphs and B-Ref. Discussion about how to improve defensive metrics is rampant at baseball sites, even in these very threads. That such admissions don't appear every time a defensive metric is invoked does not suggest to me a serious issue with the SABR community. And I say that as someone who can't stand certain baseball writers. But generally assumed precision/perfection is not the reason.

Levi, last time: they are saying "factor in positioning" as in "filter/remove/isolate the factor of positioning". I think that's a valid use of the phrase, if one is honestly attempting to consider what they are saying.. Please think about your interpretation. If the UZR estimate actually did not include the effect of shifts or positioning, it would actually be a BETTER metric in many ways than the actual UZR. They are admitting that it is a weakness of the metric that they can't consider that factor for removal. I am not going to log a complaint with Fangraphs due to your stubborness to consider what they are saying.

So you want every internet post about the metric to include some kind of disclaimer? That seems pretty unnecessary, especially since you admit being aware that no one actually believes these metrics are precise/perfect.

IT LOOKS AT THE RESULT OF THE PLAY, WHICH INHERENTLY INCLUDES POSITIONING AND SHIFTS. It doesn't parse out the credit/blame to shifts or positioning. How is this so hard to understand? If they actually had a way to remove the effects of shifts and positioning from the metric, that would actually be a very valuable thing!!! That's what is hoped to do with FieldFX type data. The end total value (player speed + reaction time + positioning/shift + whatever), in context neutral run form, will probably be somewhat close to the UZR estimates, though.

UZR estimates a player's ability to convert opportunities at his position into outs, and compares it to his peers. Criticizing it for not spitting out virtually the same value every year for a player is misunderstanding what it does. It's not trying to show "true talent" levels, which is basically impossible to do in anything more complex than perhaps a 40 yard dash. Criticizing it for not correlating great with runs on the scoreboard also misunderstands what it does. It's not trying to be Win Probability Added for defense (a highlight reel catch with the bases loaded does not demonstrate more ability in the defender than the same catch with the bases empty). And pointing out that its highest and lowest estimates over a given sample might represent outliers doesn't invalidate the metric.

Also, I am pretty sure that very very few people involved in sabermetrics think they are precisely or perfectly measuring anything. It's widely acknowledged that the only precise, perfect measurement is the one that shows up on the scoreboard; sabermetrics is all about estimating the myriad factors that go into that simple number.

It really doesn't help when people can't distinguish "isolate the effect of positioning" from "factor in positioning"

The math comment was about your questioning markos's "500 chances" example, the fitting estimated UZR into unadjusted real world run differentials, etc. You seem to not understand what UZR is trying to do, which sort of precludes detailed mathematical discussion of it. If you think sabermetrics has no room for maybe's or possibly's, you are probably railing against a caricature of a sabermetrician than the actual field. (Admittedly a few people probably resemble that caricature, but they are not here.)

OBP is more important than K rate on offense. OBP against is more important than BB rate for pitchers. If two pitchers have similar OBP against, K rate is a better tiebreaker than BB rate. Oh, those nutty "sabr people"!

This seems like a bad system. Most people probably agree that most of the prospects after the top 20 or so are pretty closely bunched in talent/expectations, yet the want to weight the #50 prospect ten times more than the #95 prospect? By that measure, having the ten prospects ranked 91-100 would not be as valuable as only having the #45 prospect.

Arcia had almost 400 MLB PA in 2013. Who had him on a prospect list entering 2014?

Not starting Santana is an extreme minority view here, scouting/stats/regression be damned. Heck, the majority might even want Escobar to start. I think some of us would just like to see the prospects get a chance to perform at the MLB level in what are known to be rebuilding seasons, as compared to trotting out middling FA options or low-upside placeholders. Like those 49 starts the 2014 Twins invested in pitchers who were gone from the organization by December for zero return value....

Thanks Markos. I still have a lot to learn about UZR. I think it would be incredible if someone would list all of a player's chances, the average run value, and the assigned run value. Maybe a further analysis could identify the types of plays that were costing Hunter, helping Gutierrez, etc. I am sure a lot of the zone data isn't free, though.

The run values are just estimates for results that happened. Just like there would be run values assigned for Joe Mauer's hits in a metric. It doesn't explain all of the factors behind those hits, but it is really the only way to "score" the results outside some kind of Win Probability Added scheme, which isn't all that useful. And fundamentally, any defensive metric based on FieldFX data is going to do the same thing. They will just be able to break down the result further, like isolate positioning, first step, etc. The total result will likely be arrived at in much the same way as UZR. All you can do is grade on the opportunities that happen, and compare to the average result of such opportunities. And given the sample sizes and the varied human factors involved, you will probably see similar noise/outliers/ranges in the total result. (And I also suspect the new FieldFX system will be even more proprietary and "black box" than current metrics, fueling even more of your skepticism.)

As to the general tone, I think most of us are in agreement, but some of us are more accepting of what an outlier value means. Outliers should invite some skepticism about that specific value, but not necessarily about the metric in general (which is the more common skepticism being expressed here).

As for why team UZR doesn't necessarily match on-field run differentials (your original question that kinda sparked the discussion), remember the UZR is a using average run values for plays. It's not based on actual game state or sequencing. The Royals may have made a lot more theoretically valuable fielding plays than the Indians in 2014, but perhaps more of them came to lead off an inning or with fewer men on base (sequencing noise). And/or the Indians had the misfortune of making some miscues of equal value as the Royals at inopportune times.

Chief, don't let the math and markos's one erroneous point cloud the issue here. The rest of markos's post was pretty great. And yes, the run value of hits to the outfield is pretty high. His point about chances is great. Say, for example, that in 2009 Gutierrez got 20 balls hit to him in very difficult but not impossible places (in the gaps, near the wall), and he is pretty darn good so he converted 15 and only missed 5. That's going to really increase his UZR because those are very difficult, valuable plays. But they are so infrequent, it is quite possible that the following season, he only got 10 similar balls hit to him due to any number of factors (random chance, weather, pitchers, hitters, etc.). And if again he misses 5, that leaves 10 fewer big value plays that he converted. Through no fault of his own, he may not have had the same chance to add that value in 2010 as he did in 2009. That alone can be responsible for a big part of his UZR swing. More factors: say Gutierrez in 2009 had an arrangement with his outfield mates and coaches that he could position himself to get more of those very difficult, big value plays. But in 2010, maybe his teammates changed, maybe his coaches changed, or maybe the teammates and coaches stayed the same but just wanted to play differently. More lost chances at big value plays. (I wonder if this is a factor in Hunter's UZR drop from LA to Detroit.) And while none of these should cause a 30 run swing alone, maybe one or more of these factors was at play, plus perhaps Gutierrez uncharacteristically missing a few more balls in 2010, plus the noise/error inherent in the samples, and all of a sudden, Gutierrez might be an outlier. That's definitely an issue with small samples of UZR. Very few people suggest trusting a single season for a single player. 3 seasons for a player, or a season for a whole team, though, and the sample gets a lot larger. And not only do some of the sample oddities tend to even out a bit, but over the larger sample, the player/team should be expected to adapt to some of these circumstances (i.e. by his second season in Detroit, perhaps Hunter should have borne some responsibility for better tailoring his defensive approach in the absence of Trout and Bourjous).

5 years (buying out 1 FA year) plus 2 team options: http://www.mlbtraderumors.com/2015/03/white-sox-extend-adam-eaton.html They now have their top 4 in 2014 WAR locked up for at least 5 years.

Slightly off topic, what is your take on the Braves new stadium situation?