From NPB to MLB: Roki Sasaki and the Challenges of Transition

For the second consecutive offseason, a Japanese "Phenom" was available.  This time, it didn't cost $700m for his services. 

Roki Sasaki, was posted as an international amateur, making him only eligible to sign a minor league deal with a bonus from the teams international signing pool -- a marquee talent at a bargain price for the team that won the "Roki Sweepstakes".

The sweepstakes concluded last night, with Sasaki joining his fellow countrymen Shohei Ohtani and Yoshinobu Yamamoto on the Los Angeles Dodgers, adding to their wealth of Japanese talent and starting pitching.

Sasaki possesses a fastball that can touch triple digits, possibly the best splitter in the world, and a slider that should translate over to the MLB if he regains some velocity.  He first burst onto the scene in the last World Baseball Classic, where he was a key player for the Japanese team that won the championship. Over four professional seasons in the NPB, he posted an outstanding 30-15, a 2.02 ERA, a 0.988 WHIP, and 11.4 K/9 rate. 

Despite being labeled a "Phenom", expectations should be tempered for the 23 year old star.  Historically, Japanese pitchers often need an adjustment period when transitioning to the MLB.  Factors like increased competition, adapting to a five-man rotation versus the NPB's weekly rotation, and cultural changes can present challenges.

Let's examine how some highly regarded Japanese pitchers fared in their early MLB seasons.

Yu Darvish, Texas Rangers

Yu Darvish signed with the Rangers after they posted a $51.7 million fee to negotiate with him. Darvish agreed to a six-year, $56 million deal (up to $60 million with incentives), bringing the total investment to $107.7 million—the most spent on a Japanese player at the time.

In NPB, Darvish dominated for five consecutive seasons with an ERA under 2.00. His final season stat line was extraordinary: 28 starts, 18-6 record, 232 innings pitched, 1.44 ERA, six shutouts, and a 7.67 K:BB ratio.

However, Darvish needed time to acclimate in MLB. In his rookie season, he posted a 3.90 ERA and a 2.48 K:BB ratio. By his second season, he looked more like the ace Texas had signed, recording a 2.83 ERA and a 3.46 K:BB ratio.

Darvish has continuously been sought after by MLB contenders, and became the first Japanese pitcher with 2000 strikeouts in the MLB

Hiroki Kuroda, Los Angeles Dodgers

The Dodgers signed Hiroki Kuroda in 2008 when he was 33 years old.  Despite his experience, Kuroda took time to find his groove.  In his rookie season he pitched to to a respectable 3.73 ERA across 183 IP.

Injuries slowed him down in 2009, limiting to 117 innings.  However, he rebounded in 2010, throwing 196.1 IP with a 3.39 ERA.  Kuroda became a reliable arm, starting five consecutive Opening Days for the Dodgers.

Masahiro Tanaka, New York Yankees

Tanaka signed a massive seven year, $155m (with a $20m posting fee) with the Yankees ahead of the 2014 season.  He was incredible in his first few starts, but suffered an injured UCL that limited him the rest of the season, but Tanaka still finished with 136.1 IP and a 2.77 ERA.  

After a step back in year 2, (154 IP, 3.51 ERA), Tanaka pitched the best season of his 7 year career in year 3, throwing almost 200 IP (199.2) with a 3.07 ERA.  

Other Notable Pitchers and Comparisons

Shohei Ohtani: His best pitching season was his third full season as a pitcher, but he's had to also focus on his hitting as well

Yusei Kikuchi: Kikuchi's last two seasons hes finally started to put it together, and was rewarded with a nice contract from teh Angels this year

Yoshinobu Yamaoto: He had a much better year than a lot of people will admit (given his record contract for a pitcher) while also battling some injuries, look for him to take a step forward in year 2

Kenta Maeda: Maeda seems like a bit of an outlier, with his first year being his best.  He's still pitching today and has put together a respectable career in the MLB.

Closing Thoughts

Transitioning from the NPB to the MLB isn't easy for anyone.  While the NPB is a highly competitive league, the MLB is the best in the world.  Add in other factors like a different pitching schedule, a different ball, language barriers, and being far from home compound the challenge of meeting lofty expectations.

Roki Sasaki has the potential to be the best pitcher in baseball, but let's not write him off immediately if he doesn't meet the lofty expectations in year one. He wouldn't be the first Japanese star to require an adjustment period -- and if history is any guide, we'll have to wait a bit to see him at his best.