Category Archives: Research

A repository for research articles

Does NPB type caste?

Three different things resonated with me recently and led to me wonder if NPB or perhaps the Japanese baseball community as a whole is molding players into particular types based on their size, speed and which side of the plate they bat from.

The first occurred during the summer while talking to foreign pitchers about their adjustments to NPB. Many, but all, mention a steep learning curve in figuring out how to put away guys who can foul off one two-strike pitch after another until the pitcher either hangs one in the zone or walks him.

This is a common type in Japan, perhaps best typified by Takuya Nakashima of the Nippon Ham Fighters, a guy who rarely drives the ball, but thrives on making contact and going the opposite way. Rather than being a home run threat, these guys are more a threat to pitchers’ mental health. What surprised me, however, was the comment, repeated a few times that these guys were left-handed hitters.

As the Texas Rangers’ Chris Martin pointed out recently when in Japan with the touring MLB All-Stars, there are right-handed hitters who belong to this class such as one of my favorite grinders, Keizo Kawashima of the SoftBank Hawks.

Toward the end of the season, I caught up with Kawashima at MetLife Dome and asked if he practiced fouling off pitches.

“No. Of course not,” he said. “OK. Not in batting practice. When I want to practice that, I do it off a machine.”

Thirteen years or so ago, at Yokohama Stadium prior to an interleague game between against the Yokohama BayStars, Lotte Marines skipper Bobby Valentine said, “Watch this guy (1.73-meter Hitoshi Taneda). He’s trying to hit them foul.”

And sure enough, Taneda fouled off a half-dozen pitches in a row to the first-base side. I don’t know yet if Kawashima and Taneda are exceptions to the rule, and I didn’t give it much thought until a few weeks ago.

I was wondering whether Koshien Stadium still cut down left-handed hitters power. A cursory look said it did, since the home run percentage of right-handed hitters was vastly better than it was for lefties. OK. Well how does that vary in other parks?

In every NPB park, right-handers hit home runs more often, because in NPB, a higher percentage of right-handed hitters hit for power.

In 2018, the median of home runs per hit for right-handed hitters with 300-plus plate appearances was 10.45 percent. For left-handed hitters, it was 7.81 percent. This wasn’t a one-year phenomenon. Power hitters have made up a smaller portion of the left-handed-hitting population in all but about 10 years over the past 68. Since foreign hitters are often selected for their ability to hit home runs, I have excluded foreign-registered players from the pool.

The third thing that struck me and helped make a chord out of these disparate themes was a memory, the memory of Ichiro Suzuki’s first career home run.

To make a long — but good — story short. Suzuki hit a solo homer in a close game against Hideo Nomo and the Kintetsu Buffaloes, and was banished to the minors by then Orix manager Shozo Doi because that wasn’t the kind of hitter he was supposed to be. He was a speedy defensive asset who was supposed to be able to go the other way and steal bases I suppose.

Annual median of HRs per hit among left- and right-handed hitters from 1950 to 2018 in NPB.

If more left-handed hitters are being pushed into a slap-hitting role, then one would expect that the median of the left-handed-hitting population would strike out less. This also appears to be true. The following table, gives the median for Ks per PA for LHB (blue) and RHB (red) with 300 PAs in each season from 1950 to 2018.


Annual median of K per PA among left- and right-handed hitters from 1950 to 2018 in NPB.

While I was at it, I did the medians for sacrifice bunts per plate appearance, stolen base attempts per times on first base, and triples as a percentage of hits. I will present these below. The big surprise is that a higher proportion of right-handed hitters have been bunting, and since 1989, a higher percentage of LHB have been would-be base stealers.


Annual median of SH per PA among left- and right-handed hitters from 1950 to 2018 in NPB.

Annual median of SB attempt per time on first base among left- and right-handed hitters from 1950 to 2018 in NPB.

It’s not a surprise that left-handed hitters are more likely to be triples hitters than right-handers. I guess the surprise is that from 1960 to 1969, there was virtually no difference between the two.


Annual median of triples per hit among LHB and RHB from 1950 to 2018 in NPB.

Hotaka Yamakawa and the art of 1st team survival

Nobody in Japan hits home runs as often as Hotaka Yamakawa, not Shohei Ohtani, not Yuki Yanagita, not anybody. So how come it took the Seibu Lions’ big bopper so long to earn playing time?

It’s complicated.

And in case you’re curious about who in NPB history with 50 or more home runs has hit them more often than Yamakawa, there are only two. One is in the Hall of Fame, one is likely to earn admission to the Hall of Fame through the expert’s division ballot within a few years. They are Sadaharu Oh (10.66 at-bats per career home run), Randy Bass (10.93) and Yamakawa (11.08).

This summer I spoke with Yamakawa several times about his early playing time mystery and he explained how an attitude adjustment — and good luck opened the door for him. You can find that story on Kyodo News here.

Complete NameABHRAB per HR
Sadaharu Oh925086810.6566820276
Randy Bass220820210.9306930693
Hotaka Yamakawa9538611.0813953488
Chuck Manuel212718911.253968254
Orestes Destrade181616011.35
Rick Lancellotti6675811.5
Ralph Bryant298025911.5057915058
Tony Solaita178615511.5225806452
Hal Breeden9217911.6582278481
Tyler Van Burkleo6565511.9272727273
Roberto Petagine283023312.1459227468
Wladimir Balentien310325512.168627451
Tyrone Woods294024012.25
Koichi Tabuchi588147412.4071729958
Larry Parrish8747012.4857142857
Alex Cabrera451035712.6330532213
Adrian Garret130210212.7647058824
Clarence Jones318224612.9349593496
Mike Diaz12569313.5053763441
Tuffy Rhodes627446413.5215517241
Gene Martin256218913.5555555556
Takeya Nakamura523338513.5922077922
Jack Howell136510013.65
Bernardo Brito6845013.68
Hideki Matsui457233213.7710843373