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How Good Is Aaron Judge Really?

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A statistical analysis of the present and future of the Yankees phenom

MLB: New York Yankees at Chicago Cubs Dennis Wierzbicki-USA TODAY Sports

Last week, Aaron Judge was named the American League Rookie of the Month for April. By all accounts, the 6-7 monster outfielder earned the recognition. He currently paces the junior circuit in home runs, runs scored, slugging percentage, and OPS, all while leading the New York Yankees (a team that was supposed to be rebuilding) to a tie for first in the ever-competitive American League East and (as of this writing) the best record in the majors.

As Judge is a twenty-five year old rookie who struggled mightily in his MLB-debut late last season, we need to address the pressing question permeating New York: can Judge really be this good?

Statistical Background

To start a piece like this, it’s always important to understand the level of performance we are evaluating. As noted in the introduction, Judge’s production for the Yankees thus far has been nothing short of astounding. Not only has the 282-pound juggernaut slugged thirteen home runs, he’s also batting .317 (top-ten in the AL) and has reached base at an envious .413 clip (third in the league), proving he can be more than a three true outcome hitter.

Additionally, Judge has afforded the Yankees a solid, consistent defensive presence in right field, making plays like this and this. Aaron’s offensive prowess often overshadows his defensive ability, but it’s important to remember that the youngster spent some time in center at California State - Fresno and some scouts thought he could stick there pre-draft. Through his combination of top-tier offensive production and solid defense, Judge has put up a remarkable 2.5 WAR in just 29 games.

What’s changed since last year?

Much of the caution surrounding Judge’s stellar opening month-plus comes from his horrendous showing in the big leagues last season.

After knocking two home runs in his first two games immediately following his call-up, the then-twenty-four-year-old sputtered to a .179/.263/.345 overall line, with just six extra-base-hits (four homers) in 95 at-bats. Most concerning for Yankees fans was his alarming 44% strikeout rate.

MLB: Baltimore Orioles at New York Yankees Noah K. Murray-USA TODAY Sports

How was Judge able to move past his poor performance last year?

First, I think I would be remiss to mention the common-sense idea of experience leading to improvement. The Yankees made the right move bringing up Judge from the minors at the end of (what turned out to be) a useless season, allowing him to get major-league seasoning, so that he could come into this season knowing what to expect.

However, there are of course deeper statistical trends that have fueled Judge’s rise. On the surface-level, actually, Judge did show what kind of player he could be in 2016. He posted a respectable 9.5% walk rate, a higher strikeout rate than usual, but he had always posted high K rates in the minors, and a slugging percentage that was not so terrible, considering he batted only .179.

What Judge has done this year, though, is dramatically expand upon the potential that he flashed in the 2016 season, but continue to use the same strategy that got him to this point: high power numbers, high walk numbers, and high strikeout numbers.

The California native still has struck out at a 26.4% clip this year, which is in line with his career average (minor + major leagues) of 25.5%; however, that is 20 percentage points lower than the total he posted last year in the bigs and is perfectly adequate considering the ways he has increased his production elsewhere.

Judge has maintained a solid 13.2% walk rate (a shade above his career numbers). And while Judge’s BABIP is high at .339, it is right in line with his career .342 average. Further, Judge has sprayed the ball around the field (48.6% pull/31.9% center/19.4% oppo) in almost exactly the same manner as he did in 2016 in the majors (46.5% pull/32.6% center/20.9% oppo).

This is a really good sign for Yankees fans. Judge has not gotten tremendously lucky, nor he is thriving in new areas outside his skill-set, which would make his performance more prone to regression. Rather, he has stayed within himself, so to speak, mitigating his weakness (strikeouts) and increasing his strengths (power and plate discipline).

Judge is swinging less and making more contact

That’s not to say, though, that Judge has not changed as a player this year.

While the traditional stats, home runs, OBP, walks, and strikeouts, stick out to us when measuring the Baby Bomber’s performance, where Judge has really made strides this year is in swinging at more strikes, taking more balls, and in recognizing breaking pitches. This has allowed him to post a high batting average and better power numbers, since he is swinging at better pitches to hit. In short, Judge is not just taking more walks, he is improving his plate discipline even in the at-bats in which he does not walk, is getting better pitches to hit, and he is hitting those pitches better.

This year, Judge has swung at fewer pitches outside the zone than last (23.9% to 33.6%), more pitches inside the zone (64.8% to 63.4%), and (when he swings) is hitting a higher percentage of pitches outside the zone (43.8% to 36.6%) and in it (84.8% to 78.9%). What this means is Judge is swinging less overall (at 40.7% of pitches this year to 45.6%) than last year and making more contact (70.6% overall contact rate this year compared to 60.2% last year).

Simplifying these numbers to how they manifest on the field, we can see through these stats that Judge has learned to wait for his pitch and become less of a free-swinger. This puts him in better position to get his pitch and make good contact on his pitch when he gets it, since pitchers are more likely to throw fastballs in hitter’s counts and it’s easier to hit a home run on a 2-0 fastball than a 1-2 fastball.

A large part of this increased plate discipline comes from Judge’s better recognition of off-speed pitches, the lack of which plagued him last year. According to Brooks Baseball, Judge has whiffed in 2017 on just 14% of sliders, 15% of curveballs, and 16% of change-ups. That’s way down from a 22% whiff rate on sliders, 24% on curveballs, and 35% on change-ups in his 2016 big-league at-bats.

Again, this is a positive sign for sustained success, since players do generally learn how to better handle off-speed pitches as they age. This home run off Alex Cobb’s off-speed pitch (at 0:51 in the clip), after Judge worked the count to 2-2, shows the main way in which Judge has improved this year.


Recently, Joe Girardi made news by comparing Aaron Judge to Derek Jeter. There may be something to that comparison in terms of each player’s demeanor and quiet confidence; however, on the field, the two could not be more different.

That’s not only because Jeter is a prototypical number-two hitter, with good speed, excellent bat-to-ball skills, a remarkable ability to get on base, and modest power, and Judge is a slugger, but also because Jeter was a lot younger than Judge when he entered the league.

Similar to Judge, The Captain debuted in (what turned out to be) a meaningless season, received a small number of at-bats (51), in a small number of games (15), and struggled (though not to the same extent as Judge struggled in 2016), before bursting onto the scene a year later and claiming Rookie of the Year honors, a title for which Judge may be the current favorite.

However, it’s easy to forget, when making this comparison, that Jeter was only twenty-one-years-old upon his debut and twenty-two years-of age when he won the ROY. Judge, on the other hand, is already twenty-five and only a year or two from his prime. That means, while we should not be too surprised by Judge’s offensive outburst, since he is reaching peak age performance-wise, we also have to temper expectations when comparing him to all-time greats.

Still, while Judge is not the next Jeter, I am confident that he will have an incredibly productive career as a Yankee. His numbers should regress a bit this season, since his current performance is out of this world, but my money is on Judge for Rookie of the Year because I think there is evidence he can sustain a somewhat-similar level of production to that he has posted so far.

Long-term, I see Judge as the sort of player who could make multiple all-star teams during his age 25-32 seasons and as an especially valuable slugger, since he does not give away his offensive value on the defensive end.

I am also optimistic that Judge is not merely a three true outcome hitter and that he can maintain a batting average anywhere from .280 to .300 due to his impressive (and improved) plate discipline, with spikes to .320 on occasion, his current level.

Now it’s your turn. How good do you think Aaron Judge can be?

Statistics are courtesy of Baseball-Reference, Fangraphs, MLBFarm, and Brooks Baseball