Have the Twins Found an Ace in Kenta Maeda?

The Twins may have found a top-of-the-rotation arm in Kenta Maeda. (via Arturo Pardavila III)

All it took to complete the long-anticipated Mookie Betts trade was the inclusion of David Price, half of his $96 million, three-year contract, a week’s worth of hand-wringing over failed medicals, and the disillusionment of an entire fanbase. In the end, Betts and Price are officially members of the Los Angeles Dodgers, while Alex Verdugo, Jeter Downs, and Connor Wong are headed to the East Coast. This blockbuster has transformed what was already a superteam into a potentially historic juggernaut in the coming season while simultaneously serving as a dour commentary on baseball’s flawed incentive structure.

The Minnesota Twins, as they often do, find themselves on the periphery of other, bigger-market clubs’ activities. Unable to iron out an agreement with Boston’s suddenly-circumspect front office, the Twins will now be sending Brusdar Graterol (along with outfielder Luke Raley) to the Dodgers in exchange for swingman Kenta Maeda and catcher Jair Camargo. While the majority of the media attention has been focused on Betts and the implications this trade has for his impending free agency, some consideration should be given to Maeda’s new employment situation. 

During his tenure as a Dodger, the versatile Maeda found himself relegated to the bullpen with increasing frequency. Between 2016 and 2017, he started in 57 of his 61 games (93.4%), while in 2018 and 2019 he occupied that role in only 46 of the 76 games (60.5%) that featured him. Furthermore, the Dodgers saw fit to limit him to 5.31 innings per start during the latter period, likely in an effort to “manage his workload,” avoid the third-time-through-the-order penalty, and distribute innings to other members of their loaded pitching staff.

It goes without saying that the Twins do not possess the Dodgers’ pitching depth and should have no qualms about slotting Maeda into their starting rotation immediately and permanently. He will join returners José Berríos and Jake Odorizzi at the top, with some pairing of Homer Bailey, Randy Dobnak, Devin Smeltzer, and  Lewis Thorpe in the four and five spots to start the season.

Michael Pineda presumably will reclaim his old job when he returns from his PED suspension in May, and Rich Hill figures to receive some consideration if and when he completes his recovery from offseason elbow surgery. If things become desperate enough that Jhoulys Chacín (who is currently signed to a minor-league contract with an invitation to spring training) gets a shot a starting, Minnesota’s on-field issues likely will extend beyond a single pitcher’s performance. That said, the acquisition of Maeda should go a long way toward improving the Twins’ ability to prevent runs.

Maeda’s primary arsenal consists of a four-seam fastball, a slider, and a change-up. He also features a curveball (typically used as a surprise pitch to open an at-bat) and a sinker. The slider, thrown a career-high 31.5% of the time in 2019, is his money pitch, posting an 18.5 pVAL and a 36.8% called-strike-plus whiff (CSW) rate last season. (To learn more about the predictive power of CSW rate, check out Alex Fast’s FSWA Award-winning article.)

For context, Patrick Corbin’s exceptional slide piece generated a 21.3 pVAL and a 37.0% CSW rate last season. The difference between Maeda’s and Corbin’s sliders lies in their respective deployment frequencies; Maeda threw his slider 31.5% of the time last season, while Corbin leaned on his a remarkable 37.1% of the time. (Jakob Junis and Clayton Kershaw were the only qualified starters to throw a higher percentage of sliders than Corbin did in 2019.)

Maeda’s secondary pitch, his change-up, also proved itself to be an effective offering, checking in with a respectable 4.2 pVAL and a 28.5% CSW rate. Though he primarily used the change-up to attack left-handed hitters (87.7% of his change-ups came with a southpaw at the plate), it’s also demonstrated an effectiveness against righties in a limited sample size, with 147 pitches thrown across 2018 and 2019 generating a 26.5% CSW rate, a 0.228 wOBA, and a 0.161 xwOBA. I would like to see Maeda be less discriminant with the pitch in 2020, as a more versatile third offering should prevent batters from adjusting to Maeda in their second and third looks at him.

The weakest link in Maeda’s arsenal is his fastball, which was hit to the tune of a 0.386 wOBA and a -0.7 pVAL last season. That’s the bad news. There are, however, reasons to be optimistic about the pitch’s future: Its 0.357 xwOBA in 2019 suggests bad luck may be partially to blame for its poor results last season. Even more encouraging is that Maeda seemed to recognize he should be less fastball-reliant while simultaneously finding a little extra oomph to put behind it down the stretch. The end result was a vastly-improved heater in the second half.

Kenta Maeda, 2019 Four-Seam Fastball Metrics (SP Only)
Date Range % of Pitches Avg. Effective Pitch Velocity (MPH) CSW% Avg. Spin Rate (RPM) xwOBA
Before 9/12 35.2 91.49 32.5 2271 0.389
 After 9/12 25.2 92.46 30.0 2313 0.318

It’s not rocket science: A fastball that’s thrown harder (and with more “rise”) should be harder to hit with authority. The fact that Maeda was able to make these improvements in his outings as a starter suggests that he can maintain them as a member of the Twins rotation. If this flashy new toy sticks around, it will give Maeda three viable options for attacking hitters in 2020.

Quietly, Maeda’s arsenal has generated some of the best results in the game. Last season, only eight starters were more proficient at inducing productive strikes than Maeda.

CSW Rate, 2019 (Min. 2000 Total Pitches)
Rank Player Total Pitches CSW%
 1 Gerrit Cole 3362 35.7%
 2 Max Scherzer 2270 34.3%
 3 Chris Sale 2466 34.4%
 4 Justin Verlander 3448 34.0%
 5 Mike Clevinger 2090 33.8%
 6 Shane Bieber 3332 33.1%
 7 Charlie Morton 3139 32.7%
 8 Lucas Giolito 2814 32.6%
 9 Kenta Maeda 2433 32.5%
10 Aaron Nola 3332 32.3%

While I’m not saying Maeda is on the same level as a Gerrit Cole or a Max Scherzer, the names on this list are undoubtedly good company for a pitcher to find himself in—assuming his goal is to rack up strikeouts and avoid walks. What about inducing weak contact? Maeda has you covered there, too:

Average Exit Velocity, 2019 (Min. 400 Batted Ball Events)
Rank Player BBE Avg. Exit Velocity (MPH)
 1 Ryan Yarbrough 416 84.1
 2 Kyle Hendricks 538 85.2
 3 Hyun-Jin Ryu 532 85.3
 4 Kenta Maeda 400 85.4
 5 Martín Pérez 532 85.4
 6 Eduardo Rodriguez 564 85.7
 7 Jacob deGrom 498 85.8
 8 Mike Clevinger 291 86.1
 9 Jack Flaherty 479 86.1
10 Zack Wheeler 580 86.2

Put it all together, and you’ve got a tried-and-true recipe for a stifled offense.

wOBA, xwOBA, and ERA- 2019 (Min. 450 Total Batters Faced)
Rank Player TBF wOBA xwOBA Diff. ERA-
 1 Gerrit Cole 817 .246 .238  .008 56
 2 Justin Verlander 847 .243 .249 -.006 58
 3 Jacob deGrom 804 .250 .253 -.003 59
 4 Max Scherzer 693 .269 .254  .015 65
 5 Mike Clevinger 499 .261 .264 -.003 56
 6 Stephen Strasburg 841 .265 .266 -.001 74
 7 Kenta Maeda 624 .274 .274  .000 96
 8 Charlie Morton 790 .270 .275 -.005 69
 9 Walker Buehler 737 .270 .275 -.005 78
10 Chris Paddack 568 .268 .275 -.007 78

Those are some men who are very good at throwing baseballs. I’ve included ERA- in the table as well, which shows Maeda ultimately was less successful from a pure run-prevention standpoint than the other pitchers named above. That’s not to say Maeda is incapable of pitching to their level in the future, or his inclusion on this list is some sort of fluke.

The reason I cited CSW rate, exit velocity, and xwOBA in writing this profile is all three of these statistics correlate strongly to future performance as well as past performance. In other words, a pitcher with below-average results that grades out as above-average in any one of these categories may be on the verge of a breakout. That Maeda stands out as well-above-average (elite, even) in all three is extremely encouraging for a pitcher who has already proven himself to be a quality major league starter.

As spring training gets underway, the Twins look to be one of the premier offenses in baseball. If Maeda can put it all together and pitch to the sum of his parts, Minnesota may have one of the better rotations in the game to back up the Bomba squad. Only time will tell.

Ryan Corkrean is a nerd about all things, but baseball in particular. He often becomes emotional while watching Mike Trout's plate appearances.
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Huh. Watched him his whole career in LA. He goes from dominant to tentative from start to start, but usually looked very strong as a RP.


I have questions about fastball volume more generally too that might make him more effective. It seems like the Twins are pretty far ahead of the curve in suppressing fastball usage?


One reason his results are so positive is because of how the Dodgers utilized him. In addition to shielding him from a 3rd time through the order and putting him in the bullpen on occasion where his stuff plays up, they also limited his BP appearances to RvR matchups. He’s truly dominant against righties but get walloped by lefties. This is problematic when starting against teams that can load their lineups with LHB. Maeda’s a nice pitcher to have in the middle of the rotation, but I’m not sure there’s potential ace here, as Dodgers did a nice job masking… Read more »