Breaking Down Rafael Devers’ Breakout Season

Chris Sale is apparently done for the year. Nathan Eovaldi is back in the rotation after his stint in the bullpen went badly. Mookie Betts is answering questions about his desire to test free agency. The Red Sox’s playoff odds look like the base of a Bryce Canyon formation, but right now, Rafael Devers isn’t just in the midst of a breakout season at age 22, he’s one of the hottest hitters in baseball.

Over an eight-game span against the Angels, Indians, and Orioles from August 9-18, Devers went 20-for-37 with 12 extra-base hits and 14 RBI, batting .541/.575/1.081 for a 324 wRC+. On August 13 against the Indians, he went 6-for-6, the first Red Sock to collect six hits in a game since Nomar Garciaparra on June, 21, 2003; four of those hits were doubles. He began the next night with a pair of hits off Shane Bieber, including a homer, to run his streak to eight straight. On Sunday, he had four hits, running his season total of four-hit games to four, one fewer than major league leader Charlie Blackmon. Unsurprisingly, Devers was named the AL Player of the Week on Monday.

Such is the nature of hot streaks that as soon as I started writing this, Devers went 0-for-4, and to be fair, one can find recent stretches — all of them relatively small sample sizes — where Gio Urshela or Aristides Aquino or Alex Bregman had better numbers, but the larger point is that the kid is in the midst of a great season during which he’s shown significant improvements on both sides of the ball. Devers entered Monday ranked second in the AL in slugging percentage (.596), third in batting average (.332), tied for fifth in wRC+ (147), 10th in on-base percentage (.380), and tied for 11th in homers (27th). His 5.5 WAR was tied with Bregman, trailing only teammate Xander Bogaerts (5.6) and you-know-who, Mike Trout (8.3).

In fact, it’s quite reasonable to call Devers the most improved player in the majors relative to last season. Using our Season Stat Grid, with a minimum of 400 PA for last year and 300 PA for this year, here’s how he stacks up in the aforementioned categories:

Rafael Devers’ Improvement
2018 .240 .298 .433 90 1.0
2019 .332 .380 .596 147 5.5
Change +.092 +.082 +.163 +57 +4.5
Change Rank 1 1 4 2 1
All statistics through August 18.

A consensus top-25 prospect entering 2017, the 20-year-old Devers made a strong showing in a 58-game stint with the Red Sox that year, batting .284/.338/.482 with 10 homers and a 110 wRC+. As Craig Edwards pointed out on May 23, his batted ball profiles in 2017 and ’18 were very similar, with the difference in performance attributable largely to luck (though a trio of trips to the injured list, two for left hamstring strains and one for left shoulder inflammation probably didn’t help):

Devers’ Batted Ball Profile, 2017 vs. ’18
2017 1.38 49.1% 35.6% 89.2 7.7 .342 .344 .310 .382
2018 1.20 46.2% 38.6% 90.7 10.9 .281 .310 .305 .379
SOURCE: Baseball Savant
All statistics through August 18.

Note the 61-point drop in BABIP and the corresponding 34-point drop in wOBA despite nearly identical xwOBA and xwOBACon. Devers did pop up more frequently in 2018 than ’17 (15.7% vs. 13.8%), and he also pulled the ball more often (37.2% vs. 34.5%), but he actually fared much better against the shift (.327 AVG/.415 SLG in 2018, vs. 283/.367 in ’17).

During the past offseason, Devers hired a nutritionist and resolved to cut down on his strikeout rate (24.1% in 2017-18). As he told MassLive’s Christopher Smith, “I’m just trying to shorten up my swing with two strikes now. And just trying to put the ball in play with two strikes to make things happen.”

Devers did put the ball in play more often in April, but largely on the ground. He made some mechanical adjustments that Craig detailed, moving to a more open stance, and the power began to show up. His groundball rate has fallen relative to last year, and he’s hitting the ball with considerably more authority:

Devers’ Batted Ball Profile, 2018 vs. ’19
2018 1.20 46.2% 38.6% 90.7 10.9 .281 .310 .305 .379
2019 1.26 42.8% 33.8% 92.8 9.7 .359 .405 .376 .430
SOURCE: Baseball Savant
All statistics through August 18.

Per Statcast, Devers’ average exit velocity has climbed from the 84th percentile to the 97th, with his xwOBA jumping from the 27th percentile to the 89th. He’s cut his rate of infield flies to 10.0%, but while his pull rate is up to 41.5%, he’s actually hitting more grounders and fewer flies than last year when he pulls, and hitting for less power under those circumstances. It’s when he hits to the opposite field that he’s been a total beast:

Devers by Batted Ball Direction, 2018 vs. ’19
Year Direction GB/FB GB% FB% AVG OBP SLG wRC+
2018 Pull 1.94 55.3% 28.5% .341 .341 .772 195
2019 Pull 3.19 59.0% 18.5% .353 .353 .636 152
2018 Oppo 0.48 27.9% 58.1% .326 .322 .535 125
2019 Oppo 0.29 16.7% 57.4% .467 .459 .944 258
All statistics through August 18.

Here’s how that oppo showing stacks up relative to the rest of the majors:

Top Batters When Hitting to Opposite Field
Rk Player Team PA AVG OBP SLG wRC+
1 Javier Báez Cubs 99 .505 .505 1.000 285
2 Jesse Winker Reds 66 .439 .439 1.061 276
3 Christian Yelich Brewers 74 .466 .459 1.027 272
4 Jackie Bradley Jr. Red Sox 68 .477 .470 .938 261
5 Rafael Devers Red Sox 110 .467 .459 .944 258
6 Nelson Cruz Twins 58 .466 .466 .897 256
7 J.D. Davis Mets 58 .518 .500 .857 250
8 Jorge Alfaro Marlins 68 .500 .485 .879 250
9 Mike Tauchman Yankees 55 .473 .473 .836 245
10 Harold Ramirez Marlins 64 .469 .469 .813 235
11 Tommy Pham Rays 82 .439 .439 .829 235
12 Shohei Ohtani Angels 75 .466 .453 .822 233
13 Bryce Harper Phillies 77 .461 .455 .829 228
14 Freddie Freeman Breaves 108 .467 .463 .822 228
15 Mike Yastrzemski Giants 53 .451 .442 .843 228

The 50 PA cutoff I used leaves David Freese (41 PA, 315 wRC+), Aaron Judge (47 PA, 296 wRC+) and Fernando Tatis Jr. (49 PA, 277 wRC+) off my leaderboard, but part of Devers’ advantage here is volume; that 110 PA going oppo is itself tied for eighth in the majors, and only two players above him have a wRC+ of higher than 150 when doing so (DJ LeMahieu for a 183 in 132 PA and Michael Brantley a 201 in 117 PA). Now, for a left-handed hitter playing in Boston, opposite field means taking aim at the Green Monster, and Devers does have a noticeable home/road split in this area, with 59 PA and a 293 wRC+ when going oppo at Fenway (eighth in the majors using a 30 PA cutoff, and still behind Bradley’s 302 in 32 PA) versus 51 PA and a 217 wRC+ elsewhere, but still — this is working.

So, too, is Devers’ improved two-strike approach:

Devers’ Two-Strike Results
2017 121 6 5.0% 47.1% .400 .304 .258 .230 .281 .434
2018 252 11 4.4% 48.0% .340 .259 .230 .198 .242 .384
2019 265 8 3.0% 33.2% .318 .296 .275 .228 .279 .419
SOURCE: Baseball-Reference
wOBA and xwOBA via Baseball Savant, other splits via Baseball-Reference.

While he’s homering with less frequency on two-strike counts, Devers’ slash stats are all much improved despite a drop in BABIP, and his strikeouts are way down. Overall, he’s cut his strikeout rate from 24.7% to 16.1%, which, yup, is the biggest drop in the majors (note that Cody Bellinger is third at -7.5%). His already-meager walk rate is down slightly, from 7.8% to 7.0%, but in light of his advances, that’s a very small complaint.

One other thing worth mentioning is Devers’ defensive improvement. Per UZR, he’s climbed from -4.6 runs in just 56 games in 2017 to -4.5 in 116 games in ’18 to 1.6 in ’19, with some of that owing to improvement in the range runs component (from 2.3 last year to 3.8 this year) and some to error runs (from -6.4 to -0.6). Via DRS, he’s swung from -1 to -13 to -2. Either way, that’s a significant contributor to his jump in value, and his current metrics more or less jibe with the future 50 grade our prospect team put on his fielding back in 2017.

While it generally can go without saying that a 22-year-old having a star-caliber season is a big deal in his team’s long-term picture, it’s particularly true in this instance, with this team facing so much uncertainty. The Red Sox, as noted previously, are carrying a $241 million payroll this year, their second over the Competitive Balance Tax threshold, and they’ve let that stop them from fortifying their bullpen either this past winter or at the trade deadline (likewise for their rotation, aside from retaining Eovaldi and more recently trading for Andrew Cashner). They have about $159 million committed to just nine players for next season, so financial flexibility could be a problem, though J.D. Martinez owns an opt-out. Given that situation, the slim likelihood of Betts signing an extension before testing free agency after next season, and a farm system that by our rankings is dead last in value, it’s vital that their young cornerstones such as Devers and Bogaerts (who’s 26 years old and signed through 2025) thrive. As this season turns sour for the defending champions, Devers’ breakout might be the best thing they have to offer.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

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London Yank
4 years ago

I thought it was a little worrying to see that Jackie Bradley Jr. has actually hit better than Devers to the opposite field. My first thought was that if a bad left handed hitter like Bradley can also be very effective when going to the opposite field, the Green Monster probably has a lot to do with it. However, Devers has actually been a slightly better hitter on the road than he has at home this year. Fenway seems to be adding loads of doubles to Devers’ output, but taking away a few home runs.