The fog of glove: how to measure defense?

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I don't understand wRC, but if you use James' runs created stat, Kemp had eight and a half more runs created than Polanco (80.3 vs. 71.8). So, that's about .85 of a win if we're using ten runs for a win. To account for a 1.9 difference in WAR, then, Polanco has to to make up 2.75 WAR in difference.

By having 26 more putouts.

timellison, Friday, 9 October 2015 02:42 (four years ago) link

Polanco has to make up 2.75 WAR difference in defense, I meant

timellison, Friday, 9 October 2015 02:43 (four years ago) link

And I'm sorry if I'm being stubborn, I understand that "more layers and adjustments" involves ways of trying to measure all of those outs - maybe how hard they were hit, how much time the fielders had to get to the balls, etc. But, again, there is such a lot of ground to be covered to account for 2.75 WAR given Kemp's better offensive numbers, same defensive numbers on balls in the zone, and maybe not that big of a difference on balls out of the zone.

timellison, Friday, 9 October 2015 02:51 (four years ago) link

Or, sorry, to account for 2.75 WAR just given the defensive differences

timellison, Friday, 9 October 2015 02:54 (four years ago) link

well the 26 outs are kind of a lot, given that polanco saw much less action in general. the other adjustments could include things like park factors, whether their respective pitching staffs give up a lot of ground balls vs fly balls, idk, other stuff. but if you're going to make an effort to understand the game, you have to be willing to admit that defense is more important -- and more complex -- than previous generations have understood. it's not difficult to envision a situation where two averagish hitters -- which polanco and kemp were this season -- could be separated due to differences in defense and base running. it's really no different than, say, mike trout being worth a couple of more wins than miguel cabrera, even though the two are both great hitters

but again as to why in this specific case it turned out this way, i couldn't tell you the exact reasons. but i do think that skepticism that a case like this could actually happen is grounded in an old-fashioned belief that defense is of negligible importance

k3vin k., Friday, 9 October 2015 03:01 (four years ago) link

http://www.fangraphs.com/library/defense/uzr/

here is a decent primer on UZR, the defensive metric FG uses, as well as why we should be using these in the first place

k3vin k., Friday, 9 October 2015 03:14 (four years ago) link

I certainly do not believe that. I'm just stating that the difference that I am seeing defensively is 26 outs. Polanco didn't see much less action - 1282 innings vs. 1220. And I'm not sure that matters anyway because Kemp played more, recorded outs, and was therefore valuable in those 62 innings that Polanco didn't play. But again, 26 extra hits for the other team, if they're average hits, should be worth about 10 runs or so. Given Kemp's 8.5 advantage in runs created, Polanco should then beat him by something like 0.15 WAR and not 1.9.

it's not difficult to envision a situation where two averagish hitters -- which polanco and kemp were this season -- could be separated due to differences in defense and base running.

Well, I think they're separated by about something like 0.85 WAR offensively overall (Kemp over Polanco), so that includes base running.

xp

timellison, Friday, 9 October 2015 03:19 (four years ago) link

I mean, the 0.85 number, as I mentioned, comes from runs created, which is a stat that seems to make sense but maybe even James didn't know why? I don't know why. At least it includes total bases so, presumably, base running.

timellison, Friday, 9 October 2015 03:22 (four years ago) link

when i say he saw less action, i'm referring to the fact that he played the same number of innings but had far fewer balls hit into his zone. (polanco played 1280 innings, not 1220, so they were essentially neck and neck.) this obviously was due to no fault of his own; likely it's due to the fact that his pitchers tend to allow more ground balls. this is a prime example of something that could be adjusted for, which would make polanco look even better in comparison

also, you might be underselling the value of a hit: http://www.insidethebook.com/ee/index.php/site/comments/run_values_of_events/

also, i don't think 10 runs created necessarily = 1 WAR. (this is obvious: kemp "created" 80 runs last season by james' (now-antiquated) method, but he certainly wasn't worth 8 wins on the offensive side.) 10 adjusted runs above average is roughly equal to that, but the two are different things

k3vin k., Friday, 9 October 2015 03:35 (four years ago) link

the way we're framing this makes it sound like polanco is some defensive wizard. he's not -- he's thoroughly average, both at the plate and in the field. hence his WAR total of about 2, which is that of an average player. kemp is (or was this year) a marginally above average hitter and an atrocious defender. polanco wasn't 25 runs "better" in the field so much as kemp was 25 runs worse

k3vin k., Friday, 9 October 2015 03:41 (four years ago) link

10 adjusted runs above average is roughly equal to that, but the two are different things

this should read above replacement, not average

k3vin k., Friday, 9 October 2015 04:12 (four years ago) link

also, i don't think 10 runs created necessarily = 1 WAR.

Neither do I, I was saying 10 runs more than another player, both above replacement level, would be 1 WAR.

I was using Polanco's numbers in right field only - 1220 innings.

the way we're framing this makes it sound like polanco is some defensive wizard. he's not

I had no intention of framing it this way at all. I was merely comparing their numbers.

timellison, Friday, 9 October 2015 04:27 (four years ago) link

10 "runs created" in the bill james sense also does not = 1.0 r/fWAR, but we're really missing the forest for the trees at this point. bottom line -- it's not hard to understand why an all-bat/no-glove guy can be less valuable than an all-around player, especially when the all-bat guy was roughly an average hitter

k3vin k., Friday, 9 October 2015 04:40 (four years ago) link

you might be underselling the value of a hit

The Dodgers this year had .496 runs for every hit, the Cardinals had .467, the Phillies had .456, and the Marlins had .432. Between the four teams, they averaged .462 runs per hit.

So, for 26 hits, that's about 12 runs and not 10.

timellison, Friday, 9 October 2015 04:43 (four years ago) link

I think the forest for the trees might actually be lost in that 0.6 WAR for a guy who was fourth in the league in RBIs but made 26 fewer OOZ putouts than Polanco.

timellison, Friday, 9 October 2015 04:46 (four years ago) link

you really love RBI huh? he was a barely above average hitter, played one of the least demanding positions on the field, and played it very poorly. even the jon heymans of the world can understand that that doesn't exactly scream "valuable player"

i also don't think it's a stretch to assume that the average hit outside an outfielder's zone is going to be worth a little more than the average overall hit

but look, if your aim here has just been about discrediting advanced fielding stats, i'm not gonna play anymore. i figured i'd at least attempt to help you understand

k3vin k., Friday, 9 October 2015 04:57 (four years ago) link

I think it's an interesting stat in that it involves actual runs, but I also think I understand all the caveats about the degree to which it's circumstantial.

My main point is that the discrepancy between the two players seems, to me at least, like a ton of mileage to account for given what we see with their offensive and defensive numbers (including the zone stats I brought up).

timellison, Friday, 9 October 2015 05:43 (four years ago) link

but i do think that skepticism that a case like this could actually happen is grounded in an old-fashioned belief that defense is of negligible importance

People always believed defense was important, but sayings like "defense never goes into a slump" used to be taken as gospel without any supporting evidence. Maybe it's more accurate to say that the value of good defense was well appreciated, at least qualitatively, but the negative value of bad defense was almost completely ignored.

i also don't think it's a stretch to assume that the average hit outside an outfielder's zone is going to be worth a little more than the average overall hit

Yes -- OOZ putouts are likely to be hit to the gaps and would go for extra bases if not caught. The average value of a single is around 0.4-0.5 runs, but I think a double is in the 0.7-0.8 range.

Does charging in on a ball and saving a single count as an in zone putout? If so, then a below average fielder might allow 10-20 balls to fall in front of him for singles per season, but "make up" for them by catching more routine fly balls due to his pitching staff.

NoTimeBeforeTime, Friday, 9 October 2015 10:02 (four years ago) link

What do you guys think of this assertion from the FanGraphs UZR Primer page:

"A typical outfield hit is worth around .56 runs and any batted ball out is worth around -.27 runs, so the difference between a hit and an out is worth around .83 runs."

The numbers I had last night showed that a hit for the Dodgers/Cardinals/Phillies/Marlins this year was worth about .46 runs. They're qualifying it by saying "outfield hits," but the number of infield hits expands that by .10? That would mean that infield hits make up 17.9 % of all hits.

And a hit for any of those four teams this year was a hit and not an out, so therefore "the difference between a hit and an out." I don't understand the premise of of subtracting another -.27 runs because it wasn't an out at all.

timellison, Friday, 9 October 2015 16:26 (four years ago) link

you should really take this up with someone with more expertise. suffice it to say that your back of the envelope calculations are less valid than the empirical data gathered by people who do this for a living

k3vin k., Friday, 9 October 2015 16:34 (four years ago) link

The numbers I had last night showed that a hit for the Dodgers/Cardinals/Phillies/Marlins this year was worth about .46 runs. They're qualifying it by saying "outfield hits," but the number of infield hits expands that by .10? That would mean that infield hits make up 17.9 % of all hits.

...no...

a hit into the outfield is going to do more damage than a hit through the infield. it's not a 1:1 relationship

k3vin k., Friday, 9 October 2015 16:36 (four years ago) link

but again, look, if it makes you feel better, you're right. kemp was the more valuable player because he had a lot of RBIs. defense doesn't matter that much. you win

k3vin k., Friday, 9 October 2015 16:37 (four years ago) link

I was skeptical about the defensive difference between Kemp and Polanco being worth something like 27.5 runs over the season based on the numbers. That is all.

timellison, Friday, 9 October 2015 16:47 (four years ago) link

ten months pass...

this has been bothering me (although i love adam eaton)

http://www.fangraphs.com/blogs/instagraphs/adam-eatons-year-for-the-ages

doesn't really inspire me to believe in current defensive metrics tho

mookieproof, Tuesday, 9 August 2016 00:52 (three years ago) link

no one is comparing him to Clemente yet

The Hon. J. Piedmont Mumblethunder (Dr Morbius), Tuesday, 9 August 2016 14:57 (three years ago) link

one year passes...

have we all seen this?

https://baseballsavant.mlb.com/catch_probability_leaderboard

ice cream social justice (Dr Morbius), Friday, 18 August 2017 19:15 (two years ago) link

two months pass...

IsBrittonInYet:
When evaluating outfield defense, how much stock do you put in Statcast’s numbers (ex. outs above average, number of 5 star catches) compared to DRS/UZR? Kevin Pillar had a DRS/UZR of 15/6 in 2017 but was -2 outs above average with no 5 star catches in 34 chances.

Dave Cameron:
It’s not about “stock”; it’s about what the information is telling you. So, for instance, Pillar’s value could come from positioning, which would mean that he doesn’t make as many plays where he has to run a long way in a short amount of time, but he’s still catching balls other worse-positioned CFs wouldn’t get to.

Also, it’s important to keep in mind that Statcast is just measuring range right now, so you don’t want to compare that measure to total DRS/UZR, which include errors and throwing arm.

If you just look at the range portion of UZR, Pillar is at +1; his +6 came from throwing and not making many errors.

ice cream social justice (Dr Morbius), Thursday, 16 November 2017 20:57 (one year ago) link

Colorado Rockies third baseman Nolan Arenado and Minnesota Twins center fielder Byron Buxton won the 2017 Rawlings Platinum Glove Award, presented by SABR. The winners were unveiled on Friday, November 10 during the 2017 Rawlings Gold Glove Award Ceremony, where the game's defensive stars accepted their hardware from some of baseball's greatest legends.

This is the first Rawlings Platinum Glove Award for both Arenado and Buxton. Arenado is the first infielder to start his career with five straight Rawlings Gold Glove Awards. Buxton is the first Twins center fielder to win a Rawlings Gold Glove Award since Torii Hunter in 2007.

The Rawlings Platinum Glove Award winners are determined by combining votes based on an adjusted SABR Defensive Index™ for each of the nine Rawlings Gold Glove Award winners in each League and the votes from baseball fans worldwide.

Based on the final SABR Defensive Index, Buxton was second in the American League with a 20.0 SDI, and Arenado was second in the National League with an 11.0 SDI.

ice cream social justice (Dr Morbius), Friday, 17 November 2017 22:13 (one year ago) link

I just skimmed this. The mere fact he's writing about baseball is encouraging enough--he mostly writes about the Cleveland Browns these days.

http://joeposnanski.com/dwar-to-end-all-wars/

clemenza, Saturday, 18 November 2017 16:13 (one year ago) link

(Love seeing Devon White's name on the CF list.)

clemenza, Saturday, 18 November 2017 16:13 (one year ago) link

seven months pass...

1) I totally buy the idea that players can bring significant value via defense.

2) I have not seen every Cubs game this year, so maybe I'm missing something.

3) I stand by my years-old contention that publicly available defensive metrics are crap when this is what they tell me. pic.twitter.com/6yo6AuoWyV

— Jeff Passan (@JeffPassan) July 5, 2018

mookieproof, Thursday, 5 July 2018 21:47 (one year ago) link

Pio:

DRS thinks Machado is a historically bad shortstop and UZR thinks he’s just regular bad. Which one do you think is closer to the truth?


Jay Jaffe:

In general, I tend to prefer DRS to UZR because of the additional observational input beyond just batted ball type (both of which do have their biases, admittedly). But I think a good strategy when viewing defensive metrics is to be wary of the outliers, and DRS tends to have more than UZR does — the spread from top to bottom is generally wider. So I’ll go with garden-variety bad instead of historically bad.

the ignatius rock of ignorance (Dr Morbius), Friday, 6 July 2018 15:00 (one year ago) link

the response to passan about schwarber's defense is that he has average-ish range and a good arm; passan's response was that that's reasonable in a vacuum, but is he really a better defender than almora or heyward? because that's what the stats are saying

mookieproof, Friday, 6 July 2018 15:55 (one year ago) link

is Schwarber particularly good at positioning or something? also i guess this might make sense if he's being strictly compared to other LFers, who are a pretty slow-footed and weak-armed lot to an extent.

omar little, Friday, 6 July 2018 16:11 (one year ago) link

https://www.fangraphs.com/library/defense/def/

sounds like they're being compared to others in the same position AND others in other positions?

na (NA), Friday, 6 July 2018 16:38 (one year ago) link

he's got a high UZR so i think that means he does well compared to other LFers ... i am not great at reading stats though

na (NA), Friday, 6 July 2018 16:42 (one year ago) link

is Schwarber particularly good at positioning or something

that might be a factor. dexter fowler's outfield defense was poor before and after he played for the cubs (esp after). whoever is shifting the OF in chicago around seems to be doing a good job of making the most out of mediocre defenders.

Karl Malone, Friday, 6 July 2018 16:53 (one year ago) link

one month passes...

fewer BIPs, less significance for defense

Unfortunately, data before 2003 is unavailable, but the stark drop in balls in play over time should make it clear that defense has become relatively less important—perhaps ground balls and hits on the infield were less prominent and this is just a shift back in the aggregate, but the increased rate of extra-base hits would lead us to believe the contrary, that infield defense was even more important in the last millennium.

In addition to fewer balls in play, though, teams have also moved to shift far more often. As Jeff Zimmerman outlined in The Hardball Times Baseball Annual 2014, shifting is in vogue. It makes sense, after all, since between 57 and 60 percent of pulled balls result in ground balls compared to 40 to 43 percent on balls hit to center and 22 to 27 percent on balls taken the opposite way. With advanced scouting and more data available, teams can better identify hitter tendencies and adjust with less risk. The fact that 24 hitters pulled at least 200 balls in play this year makes it even easier to do for the high-pull hitters (as Zimmerman notes, the top-20 players hitting into a shift accounted for over 2,500 plays in 2013, dropping their collective BABIP by 37 points in those situations).

https://www.fangraphs.com/tht/infield-defense-changes-with-three-true-outcomes/

a Mets fan who gave up on everything in the mid '80s (Dr Morbius), Friday, 10 August 2018 15:38 (one year ago) link

Best fielders in baseball per DRS:
1. Matt Chapman
2. Harrison Bader
3. JaCoby Jones
t4. Nick Ahmed/Lorenzo Cain/Miguel Rojas/Andrelton Simmons

Worst:
1. Charlie Blackmon
2. Adam Jones
3. Asdrubal Cabrera
4. Amed Rosario/Eduardo Núñez/Nick Castellanos/Miguel Andújar

— Baseball Reference (@baseball_ref) August 16, 2018

mookieproof, Thursday, 16 August 2018 21:07 (one year ago) link

Amed Rosario may be a terrible fielder but at least he has a 636 OPS. -1.1 bWAR this year

Screamin' Jay Gould (The Yellow Kid), Thursday, 16 August 2018 21:29 (one year ago) link

one month passes...

directional outs above average: https://baseballsavant.mlb.com/directional_outs_above_average

kinda wonder if bader's numbers toward LF are skewed by marcell ozuna's shoulder injury -- recently saw bader come wayyy into left to take a sac fly attempt

mookieproof, Tuesday, 18 September 2018 16:26 (one year ago) link

two weeks pass...

Athletics vs Yankees at 3rd Base

Matt Chapman: 29 Defensive Runs Saved (most at 3B in MLB)

Miguel Andjuar: -25 Defensive Runs Saved (fewest in MLB)

This image shows difference in how often Athletics/Yankees get outs on grounders near 3B pic.twitter.com/5xGiQwdSti

— Sports Info Solutions (@SportsInfo_SIS) October 3, 2018

Karl Malone, Wednesday, 3 October 2018 17:51 (one year ago) link

this seems like a more relatable, easier to understand way to communicate defensive stats

Karl Malone, Wednesday, 3 October 2018 17:51 (one year ago) link

nine months pass...

The Mets right fielder just launched himself full speed into the netting at Guaranteed Rate Field, which extends all the way down to the foul pole, to make a great catch. Extended netting is going to change some outfielders' approaches.

Manfred Hemming-Hawing (WmC), Thursday, 1 August 2019 19:27 (two months ago) link

https://atmlb.com/318BlNz

Not full speed, but a dangerous play if the net hadn't been there.

Manfred Hemming-Hawing (WmC), Thursday, 1 August 2019 20:00 (two months ago) link

guy is hitting .331 and he's just the "Mets right fielder"? c'mon

a Mets fan who gave up on everything in the mid '80s (Dr Morbius), Thursday, 1 August 2019 20:05 (two months ago) link

I leave all the little details to you, Morbs.

Manfred Hemming-Hawing (WmC), Thursday, 1 August 2019 20:08 (two months ago) link


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