As we wait to find out which team placed the winning bid for the right to negotiate with Yu Darvish, the right-handed ace of Japan's Hokkaido Nippon-Ham Fighters, it is very tempting to be cynical about Darvish's chances for success in the major leagues. Just three pitchers who made the jump from Nippon Professional Baseball have had more than two seasons in the major leagues in which they have been worth two or more wins above replacement (roughly the value of a league-average starting pitcher over a single season) according to Baseball-Reference's WAR. Furthermore, only a dozen have managed more than 2.0 bWAR over their entire major league careers.
That lack of sustained success in the majors by NPB exports would seem to suggest that pitching effectiveness in NPB doesn't translate particularly well to the majors, throwing cold water on the fevered anticipation of Darvish's arrival in the States. However, a closer look at the sample from which those statistics are drawn shows that there is actually very little precedent for a pitcher of Darvish's quality and youth making the jump to the major leagues, which makes any conclusion about Darvish's chances of success in the majors drawn from the collected careers of those NPB exports anecdotal at best and most likely outright misleading.
There have been 38 men born in Japan who went on to pitch in the major leagues. Eight of those men, five of whom grew up outside of Japan, made their professional debuts in the United States. Including two men born in South Korea (Sang-Hoon Lee and Dae-Sung Koo), just 32 pitchers came to the major leagues after first pitching in NPB. In large part because NPB players interested in pitching in the major leagues have to either be posted by their teams, as Darvish has been, or wait until after their ninth season to become an international free agent, as recent Orioles signee Tsuyoshi Wada did, just five of those 32 expatriates were 26 or younger in their first major league season. Wada will be 31 next season. Darvish, if he does sign with a major league team, will be 25 for the majority of his first season in the majors.
Already the sample of comparable pitchers is minuscule, and it quickly shrinks by more than half when you look at the careers of those five pitchers prior to their arrival in the United States. Masanori Murakami, who became the first Japanese major leaguer when he was effectively loaned to the San Francisco Giants for the 1964 and '65 seasons, threw just two innings across three games for the Nankai Hawks at age 19 before joining the Giants the following year. Lefty Takashi Kashiwada appeared in 34 games, all in relief, over four seasons with the Yomiuri Giants before being similarly loaned to the Mets for the 1997 season at age 26. Tomo Ohka, who pitched for five major league teams from 1999 to 2009 and ranks second among all Asian-born pitchers in games started in the major leagues, threw just 20 innings, most of them in relief, across parts of four seasons with the Yokohama BayStars before being sold to the Red Sox and making his major league debut at age 23.
That leaves just two pitchers who came to the major leagues prior to their age-27 season after having established themselves as impact pitchers in Nippon Professional Baseball. You might have heard of them: Hideo Nomo and Daisuke Matsuzaka. Nomo became the first Japanese major leaguer since Murakami when he signed with the Dodgers in 1995 after ending a contract dispute with the Kintetsu Buffaloes by retiring from NPB. Matsuzaka was posted by the Seibu Lions after the 2006 season and cost the Red Sox $51,111,111 for negotiating rights and another $52 million for the six-year contract that brought him to the States. Both had won the Eiji Sawamura Award (the Japanese equivalent of the Cy Young) prior to coming to the States, as has Darvish, and both were 26 in their first major league season.
Nomo caused a sensation when he arrived in the U.S. He beat out Chipper Jones for the National League Rookie of the Year award in '95, threw a no-hitter in pre-humidor Coors Field and finished fourth in the Cy Young voting in 1996, and averaged 234 strikeouts (10.1 K/9) over his first three major league seasons. Thereafter he bounced around as a roughly league-average starter but did throw another no-hitter and lead the American League in strikeouts for the Red Sox in 2001 and had two strong seasons after returning to the Dodgers in 2002.
By any measure, Nomo remains by far the most successful Japanese pitcher in major league history, turning in seven seasons worth two or more bWAR (Ohka is second with four such seasons), and compiling 20.6 bWAR for his career, nearly twice that of the next man on the list, former Dodgers closer and newly inked Diamondbacks reliever Takashi Saito (11.1 and counting).
Matsuzaka, on the other hand, has been a disappointment. Also arriving in the States at the age of 26, Matsuzaka didn't earn a single first-place vote for the Rookie of the Year award in 2007, finishing fourth in the voting. In his sophomore season he finished fourth in the Cy Young voting thanks to an 18-3 record and 2.90 ERA, but he didn't pitch nearly that well. He walked five men per nine innings, averaged less than six innings per start for a total of just 167 2/3 on the season (the fewest ever by a starting pitcher with 18 or more wins) and got by largely via unsustainable clutch pitching (his opponents hit just .164/.288/.288 with runners in scoring position) propped up by good luck on balls in play.
Since then, Matsuzaka, who butted heads with the Sox over his claim in 2009 that his ethnicity required him to train differently, has been healthy enough to make just 44 starts across three seasons while posting a 5.03 ERA across 250 1/3 innings. He will miss at least half of the coming season, the last of his six-year contract with Boston, following June 2011 Tommy John surgery.
Matsuzaka's struggles are the primary source of the cynicism over Darvish's chances for stardom in the major leagues, which is, frankly, absurd. However, I would argue that such conclusions are not racist, as many have alleged, but more simply bad science. Matsuzaka's experience is relevant to Darvish because they are comparable pitchers making similar transitions from a specific foreign league to the majors, but that single data point is of almost no value in the absence of a meaningful larger sample.
That said, here's a quick look at how Darvish, Matsuzaka, Nomo and three other successful NPB pitchers who came to the majors in their late 20s faired in their final two seasons in Japan (note that some statistics are unavailable):
Per the above, Darvish is the best young pitcher ever to attempt to make the transition from Nippon Professional Baseball to the major leagues. If there's anything we can glean from the struggles of Matsuzaka, the only of the other five pitchers above who came close to Darvish's performance in his final two seasons prior to arriving in the major leagues, it is that that transition is not always an easy one. Beyond adjusting to a new league, there are cultural aspects that come into play off the field: the language barrier, adjusting to new surroundings, a new diet, a new level of fame and fortune and a new life on the other side of the world thousands of miles from home and family.
In Darvish's case, his move to the major leagues (which is not guaranteed; the winning bid only guarantees the right to negotiate with Darvish, who it has been said would be content to remain with the Fighters should he not be able to reach a satisfactory agreement with the winning team) comes on the heels of a divorce, stacking one radical life change on top of another and separating him from his four-year-old son. However, the fact that Matsuzaka, Irabu and Igawa especially struggled to make that transition doesn't mean Darvish will as well. Indeed, those pitchers' struggles in the majors are no more a guarantee of failure than Darvish's dominance in Japan is a guarantee of success in the major leagues.