«

»

Jan 01

New Year’s Resolution: Learn More About UZR

The full title of this exercise is New Year’s Resolution:  Learn More About UZR, My Definition of a Boombastic Fielding Statistic.

-Compact disc to the prime is optimist, fans and friends I’m universally cosmic

The lead up to and the actual acquisition of LF Jason Bay by the Mets involved a lot of discussion about UZR and it’s merits or lack thereof.  My goal in writing this post is to learn more about defensive metrics in general and UZR specifically.  I claim no expertise of the subject.  This post (and hopefully resulting comments) could be considered both an educational tool for myself and anyone reading it, and also a cry for help.

In order to better understand where I’m coming from I think I must reveal a few things about myself.  That’s convenient because another one of my New Year’s Resolutions is be more open and honest about myself with others.  So here goes.

I am not a math expert.  In fact, math was one of my worst subjects in school after roughly 6th grade.  Once math class began to concentrate on Algebra, Geometry or Trigonometry, I was hopelessly lost at sea.  Unfortunately the Math Patrol Boat never came along and plucked me from the cold math water, wrapped me in a warm math blanket and fed me some warm math soup.  Worse still, the Lets Go Smoke A Joint In The Woods Behind The Maintenance Building Patrol Boat came by more than a few times.  So any brain cells that may have absorbed some of the tenets of these subjects were probably lost somewhere in the woods behind the maintenance building.  Worst of all, Danica McKellar’s books were written too late to save me.

You've come a long way Winnie Cooper

You've come a long way Winnie Cooper

So I don’t come at this subject from any particularly geeky or nerdy perspective.  I have noticed that some people who don’t embrace UZR react to it by saying anyone who espouses it “has never played the game” and “needs to get out of the lab.”  That’s just ignorant and avoids dealing with the existence of 21st century statistics.

-When I kick rhymes there’s something said to do damage, hits so strong even superman needs a hand

In my attempts to learn more about it the one thing I’ve learned for sure is that it’s not simple or easy, at least not for me.  The fine folks at Baseball Think Factory couldn’t even explain it in one part.  For those of you interested enough to read the explanation for yourselves, be sure you’re in a comfortable chair and have plenty of free time before clicking through to read Part 1 and Part 2.

I have read both parts twice and the only thing I’m confident I got out of it was a headache.  But there are a few important points that I believe I got from it and it is these points that I wish to share, and it is these points with which I need your help to make sure I haven’t taken them incorrectly.

I don’t want to discuss Jason Bay specifically because I fear any discussion will get bogged down either because of some emotional involvement in Bay as a player, or because I simply make a mistake in trying to convey something I believe I have learned about his defense.  UZR statistics first came into play in 2002.  So in order to discuss them without getting bogged down I am going to discuss them in a more general way.

To begin my explanation of what I believe I know about defensive metrics I am going to start by talking about Lee Mazzilli and home runs.  Strange, yes, but bear with me.  If you’ve come this far Mazzilli and his home runs will make sense later.

I actually brought photos of Mazzilli with me to haircuts as suggestions

I actually brought photos of Mazzilli with me to haircuts as suggestions

During Mazzilli’s first go-round with the Mets from 1976-1981, I grew from an 11 year old boy to a 16 year old young man with a driver’s license.  They were years of tremendous growth (and some fun trips to the woods behind the maintenance building) and Mazzilli was an important part of them.  One of the most interesting, odd things I noticed about Mazzilli was that he hit exactly 16 home runs in 3 consecutive years.  I haven’t studied how often major leaguers hit exactly the same number of home runs in 3 consecutive years so maybe it’s not so odd but to me at the time it was.

Now the astute among you have already searched your memory banks or favorite website and are thinking “Grave, Mazzilli never hit 16 home runs in 3 consecutive years, what are you smoking?”  For those of you who don’t already know, Mazzilli hit 16 home runs in 1978 and 1980, and 15 home runs in 1979.  But in 1979 Mazzilli hit a home run (which tied the game) in the All-Star game, thus 16 home runs in 3 consecutive years.

The number of home runs Mazzilli hit isn’t so much the point, he’s just a familiar figure I’m using in an attempt to draw you in.  Hopefully it worked.  Because you see my point about Mazzilli’s home runs is not how many he hit, but how does the number of home runs he hit compare to his fellow players.  I know Mazzilli was primarily a center fielder then with the Mets and I know that he hit 16 home runs, but how do I know how that compares with other center fielders of his era?  Well, I don’t know.  I do know I’d have to do a lot of research to find out the answer.

-Why must I try to lie and build an alibi,  when all you ask is just for me to be me

What I believe UZR does is compare any fielder at his specific position to every other fielder at his specific position in any given year.  Lets pretend that for 3 consecutive years Mazzilli had an UZR of 3.7 as a center fielder.  I believe this does not mean his performance was exactly the same in center field each of those 3 years.  I believe this does mean that compared to the average performance (actually the mean performance) of all center fielders in each of those 3 years, Mazzilli saved 3.7 UZR runs more than the average.

I believe this average or mean performance fluctuates annually depending upon the performance of all center fielders.  So any one of Mazzilli’s hypothetical 3.7 UZR years may have been more or less impressive than another, depending on the performance of all other center fielders playing that year.

Unlike 16 home runs, which tells us very little about the player’s power in comparison to any other player by virtue of the number 16 alone, a 3.7 UZR tells us almost everything about a player’s defense compared to his peers.  I believe it is formulated specifically so that in looking at any player’s UZR for any one position in any one year we can tell precisely how that player compares to his peers at his position.

Bay saves drowning Mets?

Bay saves drowning Mets?

So back to Jason Bay if I dare.  For left field in 2009 Jason Bay had an UZR of -13.0, which I believe tells me that compared to all other left fielders for the 2009 season, Bay allowed 13 more UZR runs than the mean performance of all left fielders.  What I believe this does not mean is that Jason Bay sucks as an outfielder.  It does not mean that we should turn away whenever he is in pursuit of a fly ball, nor does it mean that we should cry ourselves to sleep about the possibility of him playing the outfield regularly at Citi Field.

What I believe it does mean is that in 2009 Jason Bay was 13 UZR runs worse than the average left fielder was in 2009.  What I believe it does mean is that, compared to his peers, he can more appropriately be described as among the worst as opposed to among the best. But we all need to bear in mind, he is still a competent major league outfielder deemed by multiple managers of multiple franchises to field his position adequately enough to be put out there day after day, especially when balanced with his offensive production.

-I sought beauty through the dust of strife, I sought meaning to my music addiction

If you’ve actually read this far, first of all kudos and thank you.  Secondly you may have noticed that I used the italicized phrase I believe a number of times.  This is where my learning process comes in.  I used that phrase because in being honest with you I had to convey that I don’t know what I expressed to be true, I merely believe that I understood enough about the metrics involved to make these statements.  If I’m wrong that’s fine, now is the time for you to jump in and comment to tell me where I’m wrong so I and anyone reading this can be less wrong in the future.

Also, I have referred a few times to UZR runs above.  To continue all this soul baring honesty, I must admit I don’t quite know the definition of UZR runs or how they compare to literal runs scored by any team during any baseball game, so some help with that would be greatly appreciated.

Thank you all and I raise a glass of champagne to anyone who has made any New Year’s Resolution.  Good luck to us all in keeping them.

-Yo, where’d everybody go?

Related posts:

30 comments

  1. metfreak

    Screw UZR can the guy hit and field ? Yes then great and welcome and here is to 2010 a fresh start for everything

  2. stickguy

    nice piece.

    I honestly don’t know how they make up UZR, but my fuzzy understanding is about what you said..

    one thing though that bothers me is saying he is a “bad outfielder” (not that you did) because his UZR (or some other metric) is low.

    From everything I have read, Bay is actually a solid OF, but what he may lack is the range of some other guys (like say Crawford). But all reports seem to say he knows how to play the position, set up, throws fine, htis the cutoff man, and catches what he can reach (and throw to the right base).

    How well all those litle things translate into UZR? Damned if I know.

    just say pagan gets to a few more balls, but Bay knows when to throw home, to the cut off guy, etc. and prevents more extra bases from being taken.

    How does UZR account for the difference, and what piece is worth more?

    Bay still seems to have decent wheels, so he has to be more mobile than Sheffield was, and certainly on par with a guy like Ibanez. I hope.

    The real problem is when you take a guy like Hundley that has no range, and no OF skills, and plop him out there. That never ends well!

    1. trs86

      This is right on. Just because Bay is not as good as some of the other full-time LF does not make him a bad OF. It makes some of them very good OF. Only a few LF were positive last year. Also, I just don’t see how any defensive measure could account for fundamentals. As I mentioned with Grave in an earlier discussion his defense very well could have been impacted by the dimensions of the park or even by manager positioning. Based on my knowledge there is no system that will actually tell us if a fielder is GOOD or not. If a guy has an OPS of .900 he’s most likely a good hitter. If Daniel Murphy has an UZR of +15 that does not make him a good 1B.

  3. stickguy

    random UZR thought: does a guy like Vicky have his UZR go up when Beltran misses 1/2 the year?

    Seems that if a player is say average (a zero UZR?), if all the guys above him don’t play (and their replacements are worse than Mr. Zero), his UZR will go way up, even though he is exactly the same defensive player?

    I’m not missing anything here, am I?

    1. trs86

      Yes based on my reading it does. So if you move DeJesus to LF or a guy like Endy gets significant playing time due to injuries then it could cause all the other LF’s UZR to go down.

  4. metsfan4decades

    My math skills are right on par with Grave’s and my understanding of UZR even less. So thanks for the uncomplicated explanation. To say I have a hard time keeping up with all these new sabermetrics would be an understatement. IMO, some have real meaning, others – not so much.

    Either way, Bay is definitely better than what we had last year manning LF – defensive wise, from Murph to Sheff. From everything I’ve read, Bay catches everything he gets to and has the instincts needed to play LF. That’s a big plus from some of the fill in replacements we’ve had out there the past couple of years…

    1. trs86

      Agreed, I keep going back to Murphy. Murphy despite what the ratings say was NOT a good 1B last year. He did not know how to play the position. Just because his range was good does not make him a good 1B. What it might show is just what his coaches said. He played it too aggressive and even took balls away from 2B.

  5. trs86

    I saw that Fransisco Loriano may be available. That would be a good move.

  6. gategem

    Heb, another fine article.

    UZR when used in conjunction with other parameters, including the more conventional measurements, can be significant in gauging a players defensive abilities.

    I don’t recall anyone as attractive as Danica McKellar in my undergraduate and postgraduate math classes. I guess in some ways things have improved since my college days.

  7. dirtysanchez

    Thanks for this grave…

    My head starts getting woozy when sabermetrics start up, one of my(many) resolutions will be to try and be able to keep up with one of case’s posts ;p

    1. CaseStreet

      Lol, you guys are lucky I failed physics. I did well in trig and calculus, though.

  8. GravediggerHebner

    If Daniel Murphy has an UZR of +15, it means he saved 15 more “UZR runs” than the mean production of all first basemen. If you don’t believe that makes him “good” I won’t argue with you because I appreciate the subjectivity of it, but IMO that makes him a valuable defensive player at his position when compared to everyone who played there in the same year.

    This is where the difference between UZR (what the player actually does) versus UZR/150 (a projection based on actual performance in actual games of what a player might do over a 150 game period). This is reflected in that Murphy’s UZR for 2009 was 4.7, but his UZR/150 was 7.6 which is projected (he played 101 games at 1B, had he actually played 150 who’s to say what it would’ve been for sure?) Therefore I’m coming to understand that using the UZR/150 stat is dangerous at least for people who have yet to play that many games at the position.

    It is important to note that for infielders UZR reflects ONLY ground balls or bunts. Pop flies or line drives are not including in the calculations. Don’t ask me why I can’t possibly tell you but knowing that helps me understand how Murphy could have actually saved runs. Watching him pick up ground balls he looked pretty good to me.

    Was he sometimes out of position and did he sometimes stray into what is typically the second baseman’s zone of responsibility? Sure, but as long as that relates to a ground ball or bunt that is factored into the equation. Had he gone into the 2B zone and flubbed a bunch of plays that would show up making his UZR less.

    The use of the words “best” or “worst” is something I’m learning should be avoided. But what some may find hard to accept is that of all (literally all) 1B in the NL for 2009, Murphy saved more UZR runs than all but one of them, Travis Ishikawa.

    Think about that for a minute. The guy some people will staunchly claim is “not a good first baseman” saved more UZR runs than 78 of 80 NL 1B. That doesn’t make him the “best” 1B by any stretch, because while doing so it’s entirely possible line drives were flying past him and pop ups were bouncing off him since for whatever reason those are not counted, but in the context of fielding ground balls, both those hit into areas where 1B are “expected” to attempt to field them as well as those hit into other areas that he nonetheless fielded, he saved more UZR runs than 78 fellow NL 1B. I don’t see how that information can just be cast aside because it doesn’t feel right. Disagree with the method if one must, but don’t dismiss the results within the method.

    As far as putting what one considers a CF into LF skewing the numbers, if that’s how one wants to look at it they may. Another way to look at it is these players by virtue of playing LF are in the overall group of people playing LF, either getting to or not getting to balls that are either hit into the zones where a LF is expected to field them or outside those zones, and turning those balls into outs. If Carl Crawford is “too good” at that for poor old Jason Bay that’s tough for Jason Bay. After all we are comparing Bay to “all” LF, not just the slow white ones.

    Unlike for infielders for whom only ground balls and bunts are counted, all batted balls are counted for outfielders, so they have more chances to either turn those balls into outs or not and therefore more opportunities to better or worsen their respective UZR.

    Of the 98 people to play LF in the AL last year, 45 of them regardless of playing time got to enough balls either in or out of their assigned zones and turned enough of those into outs that they “saved” runs, albeit the plural “runs” is inappropriate because only 20 of them saved at least 2 UZR runs, the other 25 saved between 1.7 and 0.1, with Crawford the leader at 17.6, DeJesus second at 14.9 and Juan Rivera third at 12.7.

    Those who are uneasy with the presence of Crawford and DeJesus in LF should at least accept Juan Rivera as a “legit” LF. For 2009, the difference between Rivera (12.7) and Bay (-13.0) was 25.7 runs. That’s a pretty big difference however one defines it.

    Rivera started 120 and subbed another 4 games so in 124 games he saved 12.7 UZR runs through his success at the combination of getting to balls and turning them into outs when compared to all other LF. Bay on the other hand in 150 games, all starts, allowed 13.0 UZR runs (saved -13.0). So for whatever reason, whether he was not getting to as many balls, or getting to them but not turning them into outs, or a combination of factors, Rivera’s defense helped his team, Bay’s hurt his team, when both are compared to all LF.

    As I said in the post, I’m not going to boycott all plays in LF when Bay is out there, but as Met fans we should be prepared for the reality that when compared to all (I stress all, because that’s how UZR works) his fellow LF, Bay will be below average defensively, since he has been every season except 2006. That’s all that I believe UZR is telling us. Simply that compared to his peers he will be below average. I can live with that as long as he’s hitting home runs and driving in runs at a pace akin to which he has demonstrated during the bulk of his career.

    1. trs86

      Again, the more I read about UZR the less I like it as a tool to actually measure if a fielder is a good at his position. It gives me no baseline that I can use from one year to the next because the baseline changes every year. A fielder can go from -5 to +5 with the same stats only because other players changed.

      I am sure Bay is not a great defender. However, I also refuse to justify his ability on something that seems to stress range over anything else and does not seem to take into account positioning, coaching, differences in field dimensions. To me if none of us really understand it why are we so ready to use it? I can understand OPS and measure it. If a player has an OPS of .900 he is a pretty good hitter regardless of if 100 other players also hit .900.

      Also back to Murphy, again does UZR measure how well he does at scooping a ball out of the dirt? How well he does at stretching for a play? Covering 1B? Positioning? I refuse to admit that Murphy was above average at 1B while Tex was below. It makes no sense at all.

      1. trs86

        Perhaps Bay will be like Ibanez and have just a miraculous turnaround to youth and have his UZR improve 20 points just by changing leagues. He was a terrible defender and now he is above average.

      2. CaseStreet

        To your first point, I’ve mentioned a few times that looking at 1 season is not enough, which is why I always use 3 seasons.

        To your second point, there is no perfect measure of how good a player is. Does ops take into account how well a hitter can get a sacrfice fly or bunt over a runner? Does it take into account when a player misses on a hit and run or works the count or swings at a ball in the dirt? Shouldn’t all those things be taken into account when considering how good a hitter is?

        It’s impossible to have a perfect stat, yet we still use them in helping us determine who is “better”, because that’s all we have.

        Maybe we should qualify everthing by saying “according to” UZR or OPS, so and so is “better”

        1. trs86

          It is true that you have many offensive categories to tell if a hitter is a “good” hitter. However, I can’t think of many bad offensive players who have an OPS of over .900.

          Also to your point on 3 years, with UZR that is faulty as well. A player could play the EXACT same defense for three years and have an UZR that looked like this. -7, 1, +8. So which is he? Each year he played the EXACT same but others in the league changed. Was he good one year but bad the next because someone else in the league changed positions or got injured?

          1. CaseStreet

            And I can’t think of any bad defensive players with a uzr of >10.

            It’s funny how uzr miraculosly agrees with the consensus that castillo is a poor fielder and utley is a good fielder. I can’t imagine why there are major league teams that use such a silly stat to help evaluate fielding. You’d think they know what they are doing.

            You guys do realize that it’s not just a bunch of stat heads who use uzr, there are teams like the mariners and rays and others that are very openly using this stat to help analyze and build their teams.

          2. Kingman 26

            Yes I definitely realize that, but playing 199 games in LF in Fenway and making one error and having 20 assists simply has to be part of the overall equation of measuring Bay as a fielder.

          3. trs86

            Not saying it’s garbage, saying it’s not the end all be all. What is your response to the fact that player with the >10 UZR could have a 5 and a -3 in 3 years and play the EXACT same defense? How does that measure player ability?

          4. trs86

            Also there are most likely some good fielding teams that use other measures. Perhaps some teams use Baseball Prospectus’s Rate or Rate2?

            Also what does UZR’s measure of Castillo and Utley have to do with it? My own eyes can tell me that one.

            UZR also had Beltran as an average to below average fielder. It never likes him. His highest positive year while with the Mets is 8.8. Beltran would the the 20th best CF last year and would lose to Franklin Gutierrez 27.1 to -8.1.

            However, according to Rate2, Beltran was at 108 slightly better than his career average of 106 and he was 110 in 2008.

            Franking Gutierrez was at 118. Certainly a good score and he did better than Beltran but at least this stat does not show Beltran as a BAD defender like UZR did last year.

          5. trs86

            Here’s another one to look at. Gomez in 2008 his range was almost 3 times higher than Beltran and their UZR looked like this 16.5 to 8.8. What is more interesting is that difference was 5 more caught balls in 17 more chances for Gomez. His outs out of expected outs was at 154/395 where as Beltran’s was 149/378. So to me that means the rest of those stats had to be based on speculation instead of shear fact.

  9. trs86

    I have tried to find something that has a baseline. Not saying we should switch and use this but it is another tool.

    Baseball Prospectus uses something called Rate: A way to look at the fielder’s rate of production, equal to 100 plus the number of runs above or below average this fielder is per 100 games. A player with a rate of 110 is 10 runs above average per 100 games, a player with an 87 is 13 runs below average per 100 games, etc.

    Thus it is a lot like OPS+ in that 100 is average. They also have Rate2: Rate2 incorporates adjustments for league difficulty and normalizes defensive statistics over time.

    Using this to look at Bay, he was one run below average in Rate and average in Rate 2. In 2008 he was terrible at 83 and was at 91 in 2007 and 101 in 2006. In comparison Crawford’s career average is 110 in LF and was 106 last year. Again, I think we can use this along with UZR as a measure but I could not tell you which one is better, can you?

    1. trs86

      Another interesting look at those stats http://www.baseballprospectus.com/dt/bayja01.php
      shows that in 2008 Bay was just bad all around but last year he was not that bad.

      By comparisons on this, it has Murphy at 82 for LF. Also Beltran was slightly worse last year at 108 instead of 110 the year before. However, using UZR it shows that he went from 8.8 to -4.8 last year and has never showed him to be a top CF. Last year Beltran was 5th among qualified CF at 8.8 and Vicki was right behind him at 6.5. This year Beltran would have been 20th with Vicki at 18th. Looking at Rate2 again Beltran was at 108 and Vicki was at 97. For 2008 Beltran was at 110 and Vicki was at 99. So both years it shows that Beltran was clearly better.

  10. CaseStreet

    Great discusion guys. I’ll be able to add to it later this week,thanks for the discussion and happy new year!

  11. joed1

    This stat really is hard to get your arms around. It seems the whole purpose of UZR is to come up with one stat that combines all the different known defensive stats combined with several speculative statistics all wrapped into one. I don’t understand how it’s presupposed which balls are those that the fielder was supposed to reach but didn’t. Based on what? I don’t know how runs prevented can be used in determining a final grade when by it’s nature it’s purely speculative. Coincidentally, the recent furor over UZR came to the forefront with the Jason Bay acquisition.

    All I hear is how UZR takes everything into consideration including arm, range, errors, etc. So I challenged my readers who are UZR supporters to answer this question…

    Bay’s range was 7th in the league, he made no errors, had 15 assist to lead MLB, and yet he is the second or third worst outfielder in baseball according to UZR. How is that even possible?

    And why are speculative stats like runs prevented weighted more than actual stats?

    In the first 125 years of baseball, you would look at those numbers I cited for Bay and the discussion of bad defense wouldn’t even come up.

    Bay has averaged nearly 9 assists a yr for 6 straight years, fields 95.7% of his total chances and has a 2.1 range.

    I got some responses that didn’t add up regarding my challenge, the first being that UZR only works with a 3 year window. (First I ever heard of that.) If that’s true, than it makes it more clunkier and hard to use for rookies and second year players.

    It just seems that there’s a lot of effort being made to fit a square peg into a round hole.

    While advanced metrics have delivered numerous new stats for better performance analysis and evaluation, UZR seems like a dud so far.

    Also, when stories began surfacing about Daniel Murphy’s great defensive prowess based on UZR to prove his case to remain the everyday first baseman, I had to laugh.

    1. trs86

      I agree completely about Murphy. Based on watching Murphy was a 1B with a lot of range. That does not make him a good 1B. I have yet to find someone who can actually explain UZR other than the range part and expected runs saved. However, as I have stressed many times, my problem is in the lack of a baseline and the fact that range is in itself subjective. You can’t use a 3 year window because a guy could be the same defender for 3 years and have 3 different scores and none of them would tell you how he would do the following year.

      Also another question, so if Luis Castillo is up and the LF comes in to right behind the IF, 2 things could happen. Castillo hits a pop up to that LF, does his UZR now go off the charts? So Castillo hits it right where the LF should have been, does the UZR now show limited range? You can’t tell me that they are basing it on where the LF is standing EVERY pitch?

    2. Kingman 26

      Joe, I have had very similar thoughts….how bad can a guy be with 199 games in LF in Fenway and 1 error and 20 assists?

      I really think the old-fashioned E and A stats, combined with the newer UZR stas, together can give a pretty good overall evaluation.

      Bay, I think, is no speedy diving Gold Glover like Beltran, but he is no butcher like Murph in LF either—he will probably nicely field anything he gets to.

      I guess how much he gets to will be one of the key debate points of 2010!

  12. GravediggerHebner

    Thank you to everybody for chiming in, I genuinely do appreciate it.

    Unfortunately one thing that I wanted to happen didn’t happen, and that was my hope/request that people with a greater understanding of UZR than I have would come and enhance my understanding of it. All I have got so far is responses from people who are opposed to it and their attempts to refute it, which is valid and fine, but I respectfully submit that none of those same people have demonstrated thus far a greater understanding of how it works, or is supposed to work, or how it fails to work, than I already have, and there is an aspect of the blind (and disillusioned) leading the blind which stifles my attempt to be further educated and to gain greater understanding.

    1. CaseStreet

      sorry grave. I’m doing some more research on UZR so I can better understand it more myself.

      1. GravediggerHebner

        No apology necessary. The idea of it being a New Year’s Resolution made it work as a New Year’s Day post, but I should’ve known better than to expect lots of traffic and input on a holiday.

        I was hoping for you and Wanny specifically and hopefully some new person who found the post through sportspyder and took pity on me to join the site and to in concert with you guys educate me. There’s still plenty of time before April.

        I just know I’ve read so much myself and failed to understand it that I’m at the point where I need someone with a better understanding (even if that understanding leads to them refuting it) to convey it to me in layman’s terms.

        I mean no offense to those who’ve refuted it thus far above, but I also can’t ignore their obvious disdain for it. Should someone who has demonstrated more of an open mind to it tell me it just doesn’t work, I’ll be more open to their persuasion than that of people who have argued strongly against it from the moment it first came up.

        Have you figured out the relationship/difference between actual runs and UZR runs? Everytime I google the phrase “UZR runs” it does not lead me to a definition, just to an article which includes the phrase.

Leave a Reply

Your email address will not be published. Required fields are marked *