Raising Aces: Examining Masahiro Tanaka’s Mechanics

The biggest news to hit the yuletide airwaves was the official posting of star NPB pitcher Masahiro Tanaka. From now through January 24th, teams are expected to scramble for the opportunity to pay the newly-adjusted $20 million posting fee and sign the right-hander. The new import process all but assures that Tanaka will receive a heftier contract than previous NPB standouts Yu Darvish and Daisuke Matsuzaka, since the bidding war now benefits the player rather than his old ballclub (much to the chagrin of Tanaka's squad, the Rakuten Golden Eagles).

Tanaka was the ace of the NPB champion Eagles, and he came in to pitch the last inning in the final game of the Japan Series to secure the championship trophy for Rakuten. The rare relief appearance came one day after an 160-pich outing in a complete-game loss to the Yomiuri Giants, and Tanaka's heavy usage patterns of the past could be a factor that affects his future performance. He has averaged a full eight innings per start over the past three seasons, frequently exceeding 130 pitches even when he fell firmly into the icy clutches of the early-20s injury nexus, which tempers the enthusiasm generated by the “25” in the age column of his baseball card.

Tanaka received a lot of acclaim in 2013, with a stat line highlighted by a perfect 24-0 record and a 1.27 ERA, including a strikeout-to-walk ratio of 5.7 to one in 212 innings pitched. He has posted a sub-2.00 ERA in each of the last three seasons (the first two of which, especially, saw suppressed run-scoring due to a less lively ball). More of a control artist than a big bat-misser, Tanaka has also made his mark by limiting the long ball, with only 18 home runs allowed in his last 611 innings of work (0.26 homers per nine innings). League context weighs heavily in this case, though, with NPB's Pacific League averaging just 0.56 HR/9 over the same period (the MLB average from 2011-13 was 0.98 homers per nine innings).

The most glowing statistic attached to the right-hander is a ridiculously low walk rate, which has sunk to 3.3 percent during NPB’s recent small-ball era. Prior to 2011, Tanaka’s career walk rate was 6.7 percent, though it was trending down. The more concerning detail emerges when one looks at the escalating rates of free passes for the other top pitchers to make the transition from NPB to MLB; Darvish went from a 5.4 percent walk rate in his final three years in Japan to a 10.2 percent mark in his first two years stateside, while Matsuzaka took his three-year NPB average of 5.7 and became a 10.9 percent dispenser of free passes in his first three years in the majors. History has not been kind to the control rates of NPB hurlers, and a pitcher who earned his paycheck by limiting walks and homers could be greeted with a rude awakening upon hitting MLB.

However, Tanaka’s stuff is legit, with a fastball that sits 90-92 mph but spikes to 96, a sharp breaking ball, and a splitter that disappears late on its path to the plate. He uses both the four- and two-seam varieties of the fastball with good movement and plus command, according to scouting reports as well as the limited footage available. His breaker has earned a slider label, though the velocity and trajectory of the pitch suggest a curve; semantics aside, his high-frequency usage of the pitch adds to the workload-related concerns with respect to his health. The best pitch in Tanaka's arsenal is probably the splitter, which features arm-side run in addition to the trademark drop, and the fastball arm action adds to the deception of the split.

So we have the stuff and we have the stats, but what about the mechanics? Does Tanaka's delivery support the numbers, and can we glean anything through observation that isn’t apparent in statistical translations? As it turns out, the results are a mixed bag.

Mechanics Report Card

For an explanation of the grading system for pitching mechanics, please consult this pair of articles.

The first thing that stands out about Tanaka's delivery is that he employs the traditional NPB pause when pitching from the windup, stopping at the top of his delivery before engaging the second gear of his momentum. The pause might do well for deception, but it can also wreak havoc on a pitcher's consistency of mechanical timing. Tanaka earned an “N/A” for his repetition grade due to the lack of footage available, but the various pause patterns erect an obstacle in the path of repetition, which is compounded by the fact that he eliminates the pause when throwing from the stretch. He did minimize the pause in 2013, going with a lesser stall than in years past, which bodes well for his ability to make adjustments.

Tanaka also features a heavy drop-and-drive as he engages his secondary burst toward the plate, collapsing the back leg as he lowers his center of gravity. The strategy disrupts his balance (which is solid during the first gear of his motion), further complicating his attempts to repeat. On the plus side, Tanaka's second gear involves strong momentum that helps to extend his stride and improve his overall grade in that category. The net result of his poor initial move and late burst is a slightly above-average grade, but the right-hander has plenty of room to improve by eliminating the pause. For inspiration, he might look to countryman Yu Darvish, who began pitching from the stretch at all times in order to hone his mechanical timing.

The plus torque that Tanaka generates is all in the hips, with a strong delay of trunk rotation after foot strike that allows the hips to create separation before the shoulders fire. The available footage indicates that he does a good job of repeating the timing and sequencing of this portion of the delivery despite the inconsistent momentum.

Tanaka’s lateral balance falls off the map after foot strike, with some spine-tilt once his rotational phase kicks in. The end result is inconsistent posture at release point that drifts from average to very poor, and though his degree of spine-tilt is not tied to any particular pitch type, there has been a large discrepancy in his posture over time. Tanaka displayed better posture a few years ago, but his head drifted further off-track during the 2013 WBC, and the trend continued into the 2013 season. By the time Tanaka was pitching in the Japan Series in November, his posture had deteriorated to minus levels.

Tanaka does the little things well, such as maintaining a stable glove position and showing an ability to track toward the target after foot strike, but the combination of inconsistent momentum, wavering balance, and drifting posture is a bad omen for Tanaka's chances of sustaining the walk rates that have distinguished his statistical record in Japan. He has demonstrated the capacity to overcome these obstacles in the past, but because of his mechanical inconsistencies, he might very well struggle to find the same success and make adjustments against patient, powerful major-league hitters.

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I expect that Tanaka will be successful on his first run through the league, but that he might face a daunting challenge as teams get multiple looks at his arsenal. Past footage indicates that the poor posture that marked his 2013 campaign was noticeably worse than what he had shown in previous seasons, and he may have to adjust his approach to find an optimal trade-off between the steeper trajectory afforded by an over-the-top motion and the consistency that can be found by harnessing his balance and posture. Tanaka's success may also be influenced by the coaching that he receives at the major-league level.

Tanaka lacks Darvish-level upside regardless of the contract that may be coming. That said, the new posting rules, combined with the shallow free agent market could make the team that wins the Tanaka sweepstakes—as opposed to bidding on the likes of current free agents Ervin Santana, Matt Garza, and Ubaldo Jimenez—happy. Tanaka might earn more than Darvish without being the Rangers ace’s equal, yet still be a solid investment for the team that secures his services.