The difference in the philosophy of pitch counts in the MLB and the NPB is an area where pitchers from Japan need to adjust when they make the jump to the big leagues. The nature of pitch counts remains a hot topic around MLB and the topic has been addressed recent in interesting articles such as The countdown to 100 pitches by Tim Kurkjian and Pitch counts an overrated stat by Hal Bodley.
100 pitches is acknowledged as the magic number around the league and younger pitchers are protected by organizations from an early stage at their career. Even though some NPB managers have implemented the 100 pitch count philosophy it is not rare to see pitchers go the distance in an effective outing surpassing the magic number. Recent outings from Yuuki Karakawa throwing 153 pitches (9.0 innings, 9H, ER) and Naoyuki Shimizu (7.2 innings, 11H, 4ER) pitching 144 pitches illustrates how teams and players are not shy about increasing their pitch counts.
The difference in the philosophy of pitch counts between the two countries comes from number of reasons, of which I will only touch on a few. The beauty of finishing the game as a starter is indoctrinated from an earlier stage, especially dramatized in the National High School Tournament at Koshien Stadium. The legendary three days at the Koshien Tournament for current Boston Red Sox Daisuke Matsuzaka has been well publicized here in the United States with his 17 inning, 250-pitch complete game followed by a relief appearance the next day and his no-hitter performance in the final of the tournament. It will be interesting to see how the pitchers in the Koshien Tournament evolve with the number Major League-minded players increasing in the Land of the Rising Sun.
Another difference between pitchers in the two leagues is how much pitchers throw during spring training, before the season starts. MLB pitchers tend to pitch every other day or have a routine schedule throwing from the mound to prepare for the start of the season. However in the NPB, there are pitchers who start the camp in full-mode, throwing 100 to 200 pitches from the mound on a given day and coming back the next with even more. Throwing a large amount of pitches before the season starts results in a routine for the pitchers and that makes it easier to throw over 100 pitches during the season.
The last point to make here is the difference in the schedule and number of games. NPB pitchers will typically make fewer starts over the course of the season than MLB pitchers, who spend the longer season of traveling around a country that is several times bigger than Japan. That requires the teams to schedule stretches with 20 straight games, compared to NPB which has a more flexible schedule with more off days. Then there are times when teams can have extra inning games which last until a winner is decided, as opposed to NPB, where games end in a tie after 12 innings. These are practical differences that affect the usage of pitchers in each country.
Japanese pitchers coming over to the MLB need to adjust to the philosophy of pitch counts here in the States, but that is obviously not the easiest thing to do as we all know that routine is important for an athlete. Coming to a different country and then adjusting to a new routine is something that only certain players can do, looking at the results from past players. Even for a pitcher such as Yu Darvish, hyped as the next big star if he ever makes the jump, adjusting to the new routine will be the key for him. So far in 2009, he has pitched a total of 153 innings in 19 total starts averaging 8.05 innings per game. He has thrown seven complete games including two shutouts and you rarely see him leave the mound before hitting 100 pitches.
As long as the nature and philosophy of pitch counts differs in the two countries, adjustments will be required for NPB veterans jumping MLB and both sides need to be aware of that reality in order for both sides to succeed.