Japanese phenom, Masahiro Tanaka, has seemed to make the transition to the MLB from Nippon Professional Baseball quite seamlessly. In his first fifteen starts, Tanaka has gone 11-3 on the mound with 127 strikeouts. This is very reassuring for the Yankees and many Major League scouts who know it can be hard to judge how well a player from a foreign league will do when they make the transition to the Majors. The talent level and style of play across the world are quite different compared to that played in the states. Many of the factors that could have made Tanaka’s transition rough have not been an issue, including the ball.

In the Japanese leagues the ball is slightly different than the ball our professionals use. This actually should not be too hard to imagine because even in the states, the ball varies depending on the regional preference, league, and skill level. For example, the ball used in the NCAA has raised seams compared to the flatter seamed MLB ball, which has been a topic debate in the NCAA. But the NCAA ball is still manufactured by Rawlings, the same company the MLB uses, giving less concern to scouts than when evaluating Japanese players.

In the Japanese leagues, they do not use Rawlings, and for years did not have a standardized ball. It wasn’t even until recently that Japan decided on using a standardized ball made by Mizuno that would be more similar to the American ball. Before that time, many teams in Japan would use their own special ball provided to them by different sponsoring companies. One team’s ball could be completely different than another as far as size and weight. After the standardization of the baseball in Japan, pitchers like Hisashi Iwakuma claimed they could manipulate the ball better than before—a possible side “effect of the lower-elasticity rubber that encases the cork center.”

The consensus though of many scouts and players who have played in both leagues is the Japanese ball is slightly smaller and has a sticky property. Unlike the Japanese ball, the American baseball, which usually comes out of a plastic wrapper, has an almost powder-like quality when fresh out of its wrapper. This quality is the reason why every player or umpire “rubs-up” the baseball with dirt or mud before use. The Japanese ball is game ready and has a better grip. This quality can make the ball easier to control and manipulate, especially with its smaller size.

As pointed out by the Sport Science team, the ball’s spin and revolutions per minute are very important to the flight of the ball. Backspin on the baseball creates lift on a four-seam fastball causing it to stay on a flatter plane and as it appears to rise. With a smaller and lighter weight ball, it is easier to generate more spin and create better and more dramatic off-speed pitches.

Tanaka’s go to strikeout pitch, his splitter, seems to not have been affected very much by the transition to the MLB. As pointed out by John Brenkus and the Sport Science team, Tanaka’s splitter is a dominating pitch because it looks like his fastball. But because of its low revolutions per minute (RPM) due to the split finger grip, it causes the pitch to drop at the last minute. He consistently throws his splitter around 87-88 mph, giving it the appearance of a fastball. At the last minute though, gravity takes over and the pitch drops dramatically.

As good a pitch as his splitter is now, it was even better in Japan. Looking at video highlights, Tanaka’s splitter had even more of a sharp drop at the last minute. Possibly due to the lighter weight ball in Japan, Tanaka could have put more spin on the ball, compared to his splitter in the US, causing a later and more dramatic break. Comparing the splitter he used in his April 9th game against the Orioles to his highlight reel from Japan, it seems Tanaka might be using his splitter in this particular game more as a chase pitch in the dirt, than one for a strike. His splitter still breaks and is a very good pitch, but it has less vertical movement and has much more of a gradual break than the break it had in Japan.

Another pitch that seems to have been affected in Tanaka’s arsenal when comparing his highlight videos is his Two Seam Fastball. For those who don’t know, a Two Seam Fastball, for a Right Handed Pitcher (RHP), will tail away from the left handed batter and can be used to jam right handers and get lefties to chase a ball outside or freeze on a ball inside that comes in for a strike. This pitch has definitely been affected by the heavier ball in the MLB. When looking at the video clips, in Japan it moved a good 5-8 inches and even had the appearance of rising up and away to the left handed batter.

With the lighter ball in Japan, it is easier for Tanaka to generate a higher RPM count, causing more tail or movement in his pitch. In his game against the Orioles on April 9th we can see him use it, but with less devastating results. In one at bat, it freezes Chris Davis, but in the other two shown in the clip, he ground outs—not humiliating swing and misses. In the April 9th game he consistently throws it around 93 mph, with the ball breaking 3-4 inches at most. It is effective when placed on the edges and corners, but cannot be left over the plate with MLB hitters and little break, compared to what he could do with the same pitch in Japan.