The Dodgers getting Yoshinobu Yamamoto to close out 2023 was an unequivocal success. He was Japan's most dominant pitcher for years before his MLB transfer and posted unbelievable numbers in NPB, and his move to LA will undoubtedly make the Dodgers the most competitive team for any future Japanese superstars looking to come over throughout his 12-year tenure with the Dodgers.
A few limitations have been noted, however; Yamamoto will be making his MLB debut, and while NPB is the most elite international league, there are some essential differences between Japanese baseball and American baseball, including the actual baseball used in games. In Japan, the ball is smaller and has a different grip that benefits spin, which inevitably leads to a tweak in the approach and mechanics of any Japanese pitcher coming over to the States, even if those changes are mostly imperceptible to viewers. Yamamoto did use an MLB-regulation baseball in the World Baseball Classic last year and competed against major league talent, but those 7 1/3 innings (with a 2.45 ERA) can't be taken as a guarantee for major league success.
Another difference between Japanese and American baseball that could be worrying for the Dodgers: pitchers in Japan only start once a week, as opposed to MLB's typical five-day rotation system. In his first year with the Dodgers, Yamamoto will be taking on a lot of work with fewer days for rest.
Dodgers have one glaring reason to worry about Yoshinobu Yamamoto
Yamamoto pitched 100+ innings in NPB every year from 2019-2023, peaking at 193 2/3 innings in 2021, which is a comforting statistic. However, factor together the new, heavier baseball and fewer days between starts, and it could give one pause.
There are still many reasons to be excited about Yamamoto. The Dodgers have invested so heavily into him (including kicking in a personal trainer and physical therapist into his contract) and must feel confident about their abilities to help him acclimate to MLB. Given their track record with pitchers, this should come as no surprise. Even still, though, the Dodgers' current rotation does have a history of being breakable. Walker Buehler missed all of 2023 and won't return until April or May, Tyler Glasnow has never pitched more than 120 innings in his career, and James Paxton's contract was just bumped down from $11 million to $7 million in guaranteed money because of a health concern.
As we anxiously await Yamamoto making his MLB debut in March, fans should, of course, anticipate greatness, but we might also temper it with some caution. His progression through his first year in MLB will be all the more interesting to track because of the adjustments he might need to make in order to live up to his record-breaking deal.