Prospect Retrospective: Masahiro Tanaka, RHP, New York Yankees

Tonight the New York Yankees will send right-hander Masahiro Tanaka to the mound against Dallas Keuchel and the Houston Astros in Game One of the 2017 American League Championship Series. Like Yu Darvish (who we studied a few days ago), Tanaka was not a prospect in the classic sense, entering Major League Baseball as a finished product, but he’s still worth examining as an example of a successful transition from Japan to North America.

Masahiro Tanaka drew fame as a high school pitcher in Japan, breaking the previous career strikeout record set by Daisuke Matsuzaka. Drafted in the first round of the Japanese draft in 2006 by the Tohoku Rakuten Golden Eagles, he immediately became a full-time starter in 2007 at the age of 18, going 11-7, 3.82 in 186 innings with a 196/68 K/BB. By 2009 he was one of the best pitchers in Japan.

He took a further step in 2011, going from one of the best pitchers in Japan to ridiculously good, posting a 1.27 ERA in 226 innings. By this point he was deeply coveted by major league teams. His 2013 season was stunning: he went 24-0 in 27 starts, posted another 1.27 ERA, with a 183/32 K/BB in 212 innings.

Tanaka was posted by Rokuten to MLB that winter and signed a seven-year contract with the Yankees. Here’s the report I wrote on him in the spring of 2014:

Japanese star Masahiro Tanaka signed with the Yankees in late January 2014, earning a seven-year contract worth eight hundred bazgazillion dollars. Well actually it was $155 million, but when you’re talking Austin Powers numbers it all bleeds together. He was extremely successful in Japan and his stuff should carry over to the majors: he has a low-to-mid-90s fastball, a plus slider, a curveball which is decent but not as good as the slider, and an excellent splitter which functions as his key out-pitch. His command is sharp and he was nigh-unstoppable most of the time in Japan. Assuming good health and no unexpected command slippages, I’d expect Tanaka to be at least a number two starter and perhaps a genuine top-of-the-rotation ace. Grade A.

Indeed, Tanaka pitched like an ace during his 2014 debut although he was limited to 20 starts by elbow problems, going 13-5, 2.77 in 136 innings, 138 ERA+, 3.1 fWAR, with a sharp 141/21 K/BB. More elbow troubles limited him to 24 starts in ‘15 and he wasn’t quite as effective, though still above-average at 12-7, 3.51, 2.3 fWAR in 154 innings.

He went 14-4, 3.07 in 199.2 innings in 2016. So far his weakest season has been 2017 at 13-12, 4.74 in 178 innings, 2.7 fWAR.

Photo by Mike Stobe/Getty Images

Tanaka has managed to avoid Tommy John surgery despite the balky elbow; he also had shoulder trouble this year. Although his velocity has held up the fastball is perhaps not the pitch it once was, a point explored by Jeff Sullivan at Fangraphs earlier this week. Tanaka at this point is relying almost entirely on his secondary pitches, his splitter in particular.

Overall Tanaka stands at 52-28 in his major league career, with a 3.56 ERA in 668 innings, ERA+118, fWAR 12.7. It seems like he’s been around forever but he’s only 28. Overall he has been pretty much as expected, a number two starter who has been dominant at his best.

That said, there’s a lot of mileage on that arm dating back to his Japan days and he’s had his share of nagging injuries since coming to the US. Tanaka can opt out his contract this winter but if it is unclear if he’ll do so. He may be best-served by staying with the Yankees and seeing if he can rebound in ‘18.