Jhonny Peralta, Defense, and Weight

Every year, around this time, players advertise themselves as being in the best shape of their lives, either because their offseason conditioning regimens improved, or because previously they were lazy. I think the players are almost always being sincere — they probably, genuinely, feel great — but as fans, we identify this as a cliche, and we generally dismiss it. For one thing, we hear this claim entirely too often. For another, it’s never been demonstrated that there’s a relationship between best shape and on-field success. Or, if you prefer, on-field improvement. It’s been studied, albeit not exhaustively so.

There’s something particular I want to examine, though, and it has to do with Jhonny Peralta. This is an article about Peralta from Friday morning. Within:

Fewer pounds would be preferable, they told him, as he headed home for the winter. He got the message and lost 18.

“It’s good,” Peralta said. “I’ve never been at this weight since I’ve been with Detroit. I finished last season at 236. I’m at 218 now.”

Peralta continues:

“Dombrowski and everybody wanted me working on my range,” he said. “That’s why I tried to get lighter. So I can be quicker, especially up the middle.”

It’s funny — everyone, a year ago, was prepared for the Tigers’ infield defense to be dreadful, what with having Prince Fielder and Miguel Cabrera at the corners. It was pretty bad, especially if you ask Rick Porcello (off the record). But at least according to the numbers, Jhonny Peralta was fine. DRS characterizes him as being about a league-average defensive shortstop. UZR characterizes him as being an above-average defensive shortstop. People talk about Peralta’s limited range, but overall, it doesn’t seem like there’s much to complain about. But we can proceed anyway.

Peralta wants to get better at defense, so he says he lost weight. A pretty significant amount of weight, for that matter, and he says he lost it in a healthy way. It’s intuitive how weight loss and better conditioning could make a defender improve. But I was curious whether we could find anything in the numbers if we looked at previous examples. So I pulled up some previous examples.

I identified 16 players who, between 2011 and 2012, claimed to have lost at least ten pounds. They lost this weight on purpose, and it wasn’t because they were ill or anything. I wanted to know what happened with their defense, so I put their season-before and season-after Fld + Pos numbers over a denominator of 1,000 innings. In this way, I get UZR, and I also account for changes in position. A year ago, did weight loss lead to defensive improvement?

Player Pre-loss Post-loss
Casey McGehee 6.9 -2.8
Evan Longoria 10.9 -3.7
Ian Desmond 1.1 9.3
Jason Heyward 3.5 10.8
Jay Bruce -5.7 -9.2
Justin Morneau -3.1 -11.8
Justin Smoak -10.8 -7.7
Mark Reynolds -21.8 -16
Mark Teixeira -2.6 1.2
Marlon Byrd 3.9 0.0
Miguel Cabrera -12 -6.4
Mike Moustakas 2.2 14.5
Nelson Cruz -12.1 -8.2
Nick Swisher -0.2 -3.9
Shin-Soo Choo -2.4 -17.9
Torii Hunter -7.7 3.6
AVERAGE -3.1 -3.0

Welp. Hard to get less meaningful than that. Some players got better, and some players got worse, but, overall, there was virtually no change within the group. What they were, defensively, in 2011, they were again defensively in 2012.

Now for the caveats. For one thing, you know about the issues with UZR. For another thing, you know about the issues with a small sample size. And what we don’t know is what these players would’ve done in 2012 if they hadn’t lost weight and trained as they did. We don’t have a control, so it could be that the -3.0 post-loss average is significant. All the players got a year older, and as players get older, defense declines. As a group, the defense didn’t decline, so that’s of interest. But we definitely don’t see a strong effect. If there’s a benefit, we’re talking about a very small handful of runs, probably.

Something to consider is the somewhat arbitrary nature of reporting baseball player weight. It’s not always listed accurately, and sometimes players report weight loss from the previous spring, while sometimes they report weight loss from the end of the year. Additionally, offseason conditioning matters only so much — all players train in spring training, and then weight can change over the course of the regular season. A player who’s lost, say, 15 pounds come the beginning of February could see his weight change again in the coming months.

Just for the heck of it, how about the players who, between 2011 and 2012, added a significant amount of weight? The table is the same as the table above.

Player Pre-gain Post-gain
Brandon Inge 4.1 15.6
Carlos Gonzalez -4.1 -12.7
Darwin Barney 7.1 11.9
Dexter Fowler -3.7 -11.9
Elvis Andrus 10.6 11.5
Franklin Gutierrez 21.6 -23.9
Freddie Freeman -17.7 -11.6
Pablo Sandoval 13.9 2.8
AVERAGE 4.0 -2.3

You could say there might be something there. All the same caveats apply, though. It’s UZR, the sample is even smaller, the players got a year older, and the whole sample might be thrown off by Franklin Gutierrez, who didn’t play that many innings in 2012. Gutierrez was also recovering from an illness, although he was more ill in 2011, when his defense was great. If you don’t trust the Gutierrez numbers, and you remove them, the average numbers balance out. If you leave them in, you get precisely this table. It’s included more for curiosity than for analysis. We need more data, and I’m thinking about collecting it.

Jhonny Peralta wants to get better in the field, so he lost a lot of weight. That’s good — it’ll make him healthier, and it could improve his durability. But we don’t have much evidence to suggest he’ll take a statistical step forward, and if you look at players who gain weight, the data also isn’t conclusive. We do need a lot more of it, however, so that’s something to keep in mind. As intuitive as it is that being in better shape could make your defense better, in reality we’re probably talking about very slight differences, if any differences at all. What’s hugely critical for defense are instincts and first steps and hand-eye coordination and arm. Losing weight could make you a little quicker, but probably not significantly so, and in Peralta’s case, it’s unlikely a matter of 18 pounds could make him more able to get to a bunch of grounders in the hole. Peralta’s range has only a little to do with his physical frame, or at least the parts of his physical frame he can change.

It’s good that Peralta’s in better shape. Maybe he’ll keep that up all season. Maybe it’ll have real, meaningful benefits. I just wouldn’t expect him to channel his inner Andrelton Simmons. What Jhonny Peralta was, Jhonny Peralta probably will be.



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Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.


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Bryan Grosnick
Member
Member
Bryan Grosnick
3 years 5 months ago

Jeff, I looked into this in a slightly different way last year, specifically in regards to Hanley and Miguel Cabrera. It’s at: http://www.beyondtheboxscore.com/2012/3/15/2872579/height-weight-and-converting-to-third-base

Great article.

salvo
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salvo
3 years 5 months ago

Maybe the norm is that if you DON’T lose weight your natural tendency is to perform worse defensively as you age. So losing weight allows a player to maintain the status quo…

TKDC
Guest
TKDC
3 years 5 months ago

I don’t know how to do this better, but considering many of these players missed significant time in either 2011 or 2012, and defensive metrics are already suspect when looking at single years, I’m not sure how meaningful this is.

Additionally, I honestly just don’t believe that actually losing weight would not be a benefit, so if there is a story here I think it is something you somewhat touched on but did not say explicitly: players are liars.

Alex
Guest
3 years 5 months ago

Could using DRS instead solve some of the sample size issues?

tigerdog
Guest
3 years 5 months ago

I would fully expect Peralta’s UZR numbers to take a significant hit in 2013, just due to natural regression. Does anyone really believe he was the third best defensive SS in the league last year? Didn’t think so. So, when the numbers aren’t as sparkly, let’s not attribute the difference to his weight- or lack thereof.

Mike
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Mike
3 years 5 months ago

A 236 lb SS? Good lord. Easy on the buffet there Jhonny.

kevinthecomic
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kevinthecomic
3 years 5 months ago

No kidding!!! I’m a 220lb financial risk manager and that’s considered beefy for this profession.

Bryan
Guest
Bryan
3 years 5 months ago

236 is more than a lot of heavyweight boxers. Crazy.

Darrell Berger
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Darrell Berger
3 years 5 months ago

Seeing Prince and Cabrera around your infield might not be a great incentive to lose weight. Peralta probably thought he was pretty nimble compared to these guys, even at his linebacker weight.

Baltar
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Baltar
3 years 5 months ago

Hadn’t thought of it that way, Darrell, but that is one beefy infield. How much did the 2B weigh?

gnomez
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gnomez
3 years 5 months ago

@Baltar – Depends on when in the season. If you’re talking about Ryan Raburn, about 180 lbs of completely dead weight.

rustydude
Member
rustydude
3 years 5 months ago

Several years ago, Peralta came into camp touting off season laser surgery for his eyes as a projected benefit to his hitting in the upcoming season. He’s definitely a guy who looks for new angles to improve.

M'n'M's
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M'n'M's
3 years 5 months ago

You should have compared 2010 Pablo Sandoval to 2011 Pablo Sandoval. He lost like 50 pounds and improved +12 runs over the previous year.

brendan
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brendan
3 years 5 months ago

didn’t really keep it off, tho, did he?

Dan
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Dan
3 years 5 months ago

“DRS characterizes him as being about a league-average defensive shortstop. UZR characterizes him as being an above-average defensive shortstop.”

They don’t work very well then.

Sometimes it seems that stats like UZR and DRS might be revealing something that can’t be easily observed with the naked eye. Sure, stats are great for that, but these defensive metrics are obviously wrong often enough that I wonder if we’re not just better off without them.

The Party Bird
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The Party Bird
3 years 5 months ago

Peralta almost never makes errors. Admittedly, he doesn’t look very smooth in the field, but that elite error avoidance is where those numbers are coming from.

gnomez
Guest
gnomez
3 years 5 months ago

Exactly. Peralta doesn’t have much range, but within his range, he’s incredibly consistent, and also has a pretty good arm for a shortstop.

Actually, your quote sounds almost verbatim like something Jim Leyland said.

Lee Panas
Guest
3 years 5 months ago

Earlier, I was looking at fielding runs based on Revised Zone Rating and Out-of-Zone plays using a method that Colin Wyers developed a few years back. I don’t know that this method is any better than any other defensive metric, but the results for Peralta made sense. According to this, he was one of the best in baseball in the zone (steady) and one of the worst outside the zone (no range). Combining the two, he was -3 runs below average. http://www.detroittigertales.com/2012/12/in-previous-posts-i-looked-at-revised.html

The Party Bird
Guest
The Party Bird
3 years 5 months ago

Minus three for Peralta passes the smell test. He’s probably not close to as good as UZR thinks he is, and he’s certainly much better than fans who only look at range think he is. Fringe average overall.

Cliff
Guest
Cliff
3 years 5 months ago

Bad conclusion. Your evidence certainly doesn’t prove that. I wouldn’t be at all surprised if weight loss significantly improved defense especially for certain positions (not 1B)

chuckb
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chuckb
3 years 5 months ago

I would like to see how this correlates with age. It seems to me that the players who lost weight (and gained weight, for that matter) were all a year older that year than they were the previous year. They probably should have been at least slightly worse defensively in year 2. The fact that their defensive performance was roughly the same may indicate that the weight loss worked to counter the effect of aging. In other words, it might mean that losing weight worked because the players would have been worse due to age had they not lost weight.

Cisco
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Cisco
3 years 5 months ago

An ambitious study with a tough to prove goal but an admirable attempt. One of the greater issues being the difference in the physical demands of each position i.e: comparing Miggy to Heyward or Inge to Fowler seems a bit unfair.

Still, nice work though. Certainly worth considering

Brandon R
Guest
3 years 5 months ago

What I’ll never understand is athletes making millions of dollars needing to be told to get in shape. Shouldnt Peralta assume that, oh I don’t know, that because he’s a SS maybe he should be relatively agile?

Ervin Santana
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Ervin Santana
3 years 5 months ago

He’s earned his millions and he is considered one of the very best in the entire world in his profession. I can certainly see why he wouldn’t worry about his weight too much.

Dennis
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Dennis
3 years 5 months ago

Do you have the change in offensive production by those same groups? It’d be interesting to see any gains/losses there measured against the changes in defense.

Voice of Reason
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Voice of Reason
3 years 5 months ago

Net Gain/Loss Ht(Inches)
Swisher -3.7 71
Choo -15.4 71
Byrd -3.9 72
Moustakas +12.3 72
McGehee -9.7 73
Longoria -14.6 74
Desmond +8.2 74
Hunter +11.3 74
Reynolds +5.8 74
Cruz +4.1 74
Bruce -3.5 75
Teixeira +3.8 75
Cabrera +5.6 76
Morneau -8.7 76
Smoak +3.1 76
Heyward +7.3 77

Circlechange11
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Circlechange11
3 years 5 months ago

My guess is that it’s easier to shed the weight in the off-season because there’s not as much late night eating and drinking.

Baltar
Guest
Baltar
3 years 5 months ago

Yep, just traveling puts on the pounds, too. What do you do on an airplane or in an airport? Probably not eat and drink in a healthy fashion.

Andrew
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Andrew
3 years 5 months ago

Sit on one’s ass.

TroutFan
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TroutFan
3 years 5 months ago

Fantastic article! Lots of statistical analysis with a horrible conclusion! Can’t wait until you guys get your hands on HOF votes.

Rustydude
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Rustydude
3 years 5 months ago

Yes, because it’s clear that the HOF would get way worse by swapping out the current set of voters.

TKDC
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TKDC
3 years 5 months ago

Fantastic comment! Absolutely worthless!

Oscar
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Oscar
3 years 5 months ago

Post some random data-mining and conclude with “well, we really can’t know anything for sure.” The Fangraphs way.

craigws
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craigws
3 years 5 months ago

“i want conclusions, dammit!!
don’t bother me with all your facts.”

Oscar
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Oscar
3 years 5 months ago

Downvotes are weird. Is there a single piece of genuine insight in this article? Is there anything in it that justifies posting it?

Seriously! Read it! There is nothing in it!

BookWorm
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BookWorm
3 years 5 months ago

TroutFan and Oscar, there’s nothing wrong with reporting a lack of definitive findings or a negative finding. In fact, it’s essential to any experimental process that we determine which hypotheses are correct, which are incorrect, and which need more study.

Just because the “data mining” or “statistical analysis” doesn’t lead to some ground-breaking discovery doesn’t mean it’s not worth reporting what you find — it can inspire others to approach the same question from a new angle.

Someone
Guest
Someone
3 years 5 months ago

Fu*king Scientific Method, how does it work?

Yokel
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Yokel
3 years 5 months ago

Commies. Thats how. Theyre gonna brainwash our youth to ensure their future world domination.

Oscar
Guest
Oscar
3 years 5 months ago

Data mining is great. But this article has no ACTUAL statistical analysis. No strength of correlation, no nothing. It’s an arbitrary sample of some numbers and then no attempt to prove, disprove, demonstrate, or anything. I wouldn’t even be posting if it wasn’t a frustrating trend for Sullivan and a lot of the others on this site. Compare this to a Dave Cameron article, or Tom Tango or Dave Studeman or Mike Fast or Pizza Cutter or etc etc.

There’s no original insight, there’s no rigor. It’s fluff. And after the twentieth one of these in two weeks, I get annoyed. This is not the scientific method.

BookWorm
Guest
BookWorm
3 years 5 months ago

We agree that this isn’t ‘statistical analysis,’ in the sense that there is no attempt to do a rigorous, parametric correlation of something like weight-change and UZR.

But my point is that one needs to start somewhere. Jeff’s article could be the first step in a conversation about where to take this for further research. And frankly, given that the information on a player’s weight is self-reported, I’m not sure there’s much better that can be done. But an article without a firm conclusion one way or the other could be seen as an invitation to do further research.

Chris from Bothell
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Chris from Bothell
3 years 5 months ago

You should definitely ask for your money back.

Adam B.
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Adam B.
3 years 5 months ago

Defensive statistics are garbage.

Yokel
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Yokel
3 years 5 months ago

Yep. And evolution. Absolutely garbage. And our country’s morals because we don’t have mandatory school prayers.

commenter #1
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commenter #1
3 years 5 months ago

feed not the trolls, they know not things

Colin
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Colin
3 years 5 months ago

To an extent this seems to depend on what you’re good/bat at. For instance, if the players problem is he makes too many errors, losing weight might not really help him.

Peralta’s problem is that he lacks some range. Peralta happens to be very good at making plays when he gets the opportunity to do so. So I tend to believe it might help him get to a few more balls.

JChang
Guest
JChang
3 years 5 months ago

I agree. I think the lost weight will definitely help his range. Especially with the little things, like turning double plays. If he’s making more difficult plays, he might make more errors though. Even if that’s the case, it would be nice to see the effort.

HtWP
Guest
HtWP
3 years 5 months ago

I notice that 3 of the players (Longoria, Morneau, and Choo) who lost weight and saw big declines in their defensive numbers also missed significant time do to injuries.

Jonathan Sher
Guest
Jonathan Sher
3 years 5 months ago

In addition to the caveats you cited, here’s more: Your comparator groups.

Among the players who lost weight who you cite, only one was a middle infielder shortstop or even a middle infielder and he saw a marked improvement in UZR, Ian Desmond. The rest of the group are largely corner outfielders and infielders and may not make suitable comparators to a shortstop.

Your weight-gain group is meant to test whether there is an opposite effect but that would only hold some validity if those players went from being out of shape to in-shape. But some of these players did not — they went from being skinny to adding some muscle — Andrus is a prime example.

Finally, while Peralta’s total defensive rating changed only marginally in 2012 his UZR range rating improved a much more substantial amount that was offset by a worsening in error rating. If the point of his weight loss was to improve his range and if you believe such small samples of UZR, then his weight loss achieved its intended effect.

tbonemacd
Member
tbonemacd
3 years 5 months ago

So do advanced fielding stats have value or not?
According to the numbers Peralta was indeed a solid SS last year, yet many commenters disregard them because they don’t fit their narrative. When some argued during the MVP battle that Trout ain’t Willie Mays and throws like Johnny Damon, the pro-Trout group point to the positive fielding numbers to fit their narrative. Can’t have it both ways…if UZR can’t be trusted yet, why use them?

MGL
Guest
MGL
3 years 5 months ago

For what it is worth, if a player or group of players is -3 in UZR one season and -3 the next season, that implies a loss in UZR talent. That is because -3 for one season or a partial season needs to be regressed, perhaps half-way towards a mean (say, zero), which puts their year X UZR true talent at -1.5. So a -3 next year means a loss of 1.5 runs in UZR talent.

That, BTW, is entirely consistent with aging. Players lose 1-2 runs a year in UZR talent at almost any age (due to aging – UZR peaks quite early, probably in the early 20’s).

evo34
Guest
3 years 5 months ago

What are you talking about? The samples are the same size. Both years would get regressed equally. Why would you assume that a -3 in year 2 is somehow more indicative of true skill than the -3 in year 1? If a group of drivers of unknown skill got into 10% more accidents than average in a given year, then the next year they also had 10% more than average, you would claim that they actually lost skill between years 1 and 2? Interesting. By that logic, a team that goes .450 win pct. in year 1 is a lot better than the same team that goes .450 in year 2 (assuming same roster and no aging)? That’s not the way it works. You have more data, so all you can say is that the true talent is closer to .450 than you first thought (after year 1). However, you cannot say that the players got worse from year 1 to 2.

mike
Guest
mike
3 years 5 months ago

Seems to me like if you wanted to try getting any kind of meaningful analysis with this you would have to get much better information on players weights and break them up into groups based on their height to weight ratios.
First off you don’t know which of your players kept the weight off for more than a few weeks into the season and which put it back on or even gained more weight.
Second, you don’t know which of your players would have been considered overweight to begin with. You have young players on there who may have actually been considered underweight who merely gained muscle weight. That’s fairly different than an overweight player with too much fat.

It seems kind of lazy to try to do this kind of analysis without really gathering the necessary data and just lumping together what little you found without thought of whether what you were comparing is actually comparable.

Givejonadollar
Guest
3 years 5 months ago

All these little things add up to make a whole. If there are fans that do not believe analysis is important, no problem, don’t come here.

Take the team that takes this stuff seriously, put them against a MLB team that doesn’t take this stuff seriously, and have them battle for 100 years and see who comes out on top.

I imagine it will be the one, consistently, that takes as much data as they can and try to see what they can learn from it.

Kevin
Guest
Kevin
3 years 5 months ago

Forget his defense, hopefully his 18 pound loss helps him swing the bat a little quicker. Just gimme 275, not asking for much!

Alaruss1942
Guest
Alaruss1942
3 years 5 months ago

I look at Jhonny’s effort to lose weight and effort to try to increase his range (I don’t think “range” can be taught) and say that he sees a really good thing happening in Detroit and he wants to his best to be a part of it. If his hittiing last year was an anomoly, and I think it was, he will be a valuable part of a championship team. If he bats 7, there should be men on base when he comes up, RBI’s should go up also. We certainly don’t have any shortstops in the pipeline if we read ann article about Cale Iorg, he can’t hit my wife’s weight, let alone mine, which would be a good average!! That makes Jhonny look all the better unless someone is willing to part with a good shortstop for Porcello or Smyly…I say let’s keep all three!

AdmiralWhiskers
Guest
AdmiralWhiskers
3 years 5 months ago

I wonder what type of effect weight loss/gain has on older players and their injury probabilities. Packing some extra pounds can do some real damage to the ol’ knees, especially for older players who play physically demanding positions. If losing 18 pounds makes it less likely that Peralta suffers an injury, then even if there is no effect on his overall defense, the ability to play in more games creates a positive effect overall.

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