Tag Archives: Bill James

Japan’s all-time greats

As the deadline for Japanese Baseball Hall of Fame ballots approaches, and people talk about who should be in the Hall of Fame — as opposed to who shouldn’t, it might be constructive to look at who are the all-time greats.

The biggest problem I find with compiling these lists is that the competition is generally better since 1990 than it was in the 1940s, 50s, 60s, and even 70s. Thus, it is far more difficult to dominate play than it was 30, 40 or 50 years ago. For that reason, a straight-line numbers comparison between a recent superstar and one from 50 years ago will almost always be one-sided.

Let’s look at how many times a player has led his league in one of the following offensive categories:

  • batting average
  • on-base percentage
  • slugging average
  • doubles
  • triples
  • home runs
  • RBIs
  • stolen bases
  • walks

Sadaharu Oh led his league in one of these categories 102 times. Seven of the top-10 leaders played the bulk of their careers in the 1950s, 1960s and 1970s. This requires an adjustment to adjust for both the era and the degree to which talent is compacted.

OK. Enough talk. Here are top 20 players in career value in NPB according to Bill James’ win shares formulas and using a competition adjustment (based on the year and the standard deviation of win shares by players with 100-plus games in a season. There may be no perfect solution to this problem but this was mine).

Top Career Totals

NameBest SeasonCareer HighCareer TotalAvg modifier
Sadaharu Oh196541.8672.91.07
Katsuya Nomura196537.5526.31.07
Isao Harimoto196434.1496.11.06
Hiromitsu Ochiai198235.5466.40.94
Masaichi Kaneda 195840459.31.08
Kazuhiro Yamauchi195640.24431.09
Shigeo Nagashima196141.4440.51.12
Hiromitsu Kadota197735.3434.71.00
Tomoaki Kanemoto200538.8434.10.94
Koji Yamamoto198038.3408.11.02

Peak value: Average of best 5 consecutive seasons

The following table represents my estimate of the players who put together the best five-season runs in NPB history.

NamePeriodAverage WSWS totalsModifier
Sadaharu Oh1964-196839.140, 42, 40, 37, 371.07
Kazuhisa Inao1957-196136.037, 40, 40, 20, 441.12
Yuki Yanagita2014-201835.231, 39, 32, 39, 360.93
Ichiro Suzuki1994-199835.038, 38, 38, 33, 280.92
Shigeo Nagashima1959-196334.836, 34, 41, 25, 381.10
Hideki Matsui1998-200234.036, 31, 36, 32, 351.00
Katsuya Nomura1964-196833.830, 38, 34, 33, 341.07
Hiromitsu Ochiai1982-198633.033, 30, 35, 34, 310.97
Masaichi Kaneda1954-195832.525, 35, 33, 30, 401.09
Shigeru Sugishita1951-195532.327, 33, 26, 43, 331.03

Hall of Fame candidates

Here are the 23 candidates on this year’s players division ballot for the Hall of Fame, with their career win shares and best-five consecutive season averages and how they rank all-time in both categories:

HOF candidates 2020

Nam eCareer WSCareer Rank + Peak 5Peak Rank
Atsunori Inaba302.24327.343
Kenji Jojima*227.26026.946
Norihiro Nakamura304.44126.062
Tuffy Rhodes319.93225.866
Hiroki Kokubo310.63725.570
Alex Ramirez247.68424.683
Takuro Ishii298.94824.191
Kenjiro Nomura243.68924.191
Akinori Iwamura168.113224.191
Norihiro Akahoshi146.228720.2175
Masumi Kuwata19116219.6199
Takeshi Yamasaki241.19418.9237
Tomonori Maeda262.37217.9274
Masahiro Kawai147.628415.7379
Makoto Kaneko179.818515.5389
So Taguchi121.923915.0412
Shinji Sasaoka171.720014.4447
Shinya Miyamoto200.614513.7504
Kazuhisa Ishii137.724313.6510
Shinjiro Hiyama137.832113.1552
Shingo Takatsu10043110.1804
2020 Hall of Fame candidates, career win share and peak win share ranks. Career win share rank includes MLB WS for Japanese players.

The months matter

A recent discussion in the “Hey Bill” feature in billjamesonline discussed why some players do better than others and brought up the topic of relative age effects. I did a study about 10 years ago about the effects of NPB players’ birth months that was published in the Daily Yomiuri, which means it’s disappeared from the web. The upshot of that study was that players born from April 2 to June 30 are over-represented in the NPB amateur draft and, on average, have less valuable careers than player born from July 1 to April 1–the cutoff date for school admissions.

Children born on April 1 will enter school in Japan a year before a child born the following day.


I replicated the study using every domestic player signed by an NPB team from the end of the 1965 season through the start of the 1997 season. Omitting four players I don’t have birth dates for, that remaining group of 2,160 players contains two active players, Ichiro Suzuki and Kazuya Fukuura. And whatever they produce in 2019 is not going to affect anything one way or another. The starting point of the study was set by the introduction of NPB’s first draft in 1965.

Breaking down each quarter of a year by birth month — with April 1 counting as March — and draft round. The most populous cell is the 127 signed first-round picks signed who were born from April to June. The second most is the 121 players born in those months taken in the second round. As expected, the 341 “haya umare” or early-born players whose birthdays go from Jan. 1 to April 1, make that quarter the least populous.

The table below gives the career win shares produced by players born in each quarter and the total number in each group, without reference to draft round.

The last thing that needs to be mentioned is the problem of value in the major leagues. Major League win shares are given 20 percent more weight in the calculations. It’s just a guess. They could be 50 percent more valuable for all I know.

Distribution of domestic players by birth-month quarters

Avg WS210.0230.5306.8223.0
Percent of total34.930.119.215.8

The favoritism in the draft show players born in the April-June quarter is exacerbated by an even higher share of those players taken in the first two rounds, and by the performance of those players.

Value rank of birth-month quarter by round

RoundQuarter starting Avg WS Best career
1stJuly68.8Kazuhiro Kiyohara, 1B
1stJanuary60.2Masaki Saito, P
1stOctober59.7Koji Yamamoto, CF
2ndOctober55.6Taira Fujita, SS
3rdOctober54.7Hiromitsu Ochiai, 1B
2nd January48.1Hiromitsu Kadota, DH
1stApril44.6Hideki Matsui, CF
2ndJuly44.5Keishi Suzuki, P
4thOctober39.0Ichiro Suzuki, RF
3rdJanuary38.8Yoshihiko Takahashi, SS


Another thing that needs to be mentioned is that the birth-month quarter starting in January is largely populated by pitchers and catchers. In my previous study, I found that more than a quarter of the players drafted as catchers were born between Jan. 1 and April 1.

When I first did this study, a number of people gave me what I’d snarkily call “baseball announcer explanations” for why players born from October to April 1 outperform the players who are chosen more often by pro teams. The most popular one of these was, “Oh, they’re used to overachieving, so they try harder.”

All these guys try hard. I think there are three things going on.

  1. Accessibility
  2. Age bias
  3. Burnout


Players who are born after April 1 are larger and physically more developed than players months younger than they are. This gives them more time to play, more time to stand out and be noticed by coaches, who select them to play so that they can be seen by scouts.

Age bias

Because players born from October to April 1 are less physically developed than the players they are competing against, they are less likely to dominate competitions when scouts are watching.


This is something that hadn’t occurred to me until recently. According to people who know a lot about how youth baseball functions in Japan, many of the players who eventually turn pro in Japan are not the best in their age groups when they are young. Amateur sports in Japan are intense, year-round, meat-grinding wars of attrition.

The best players typically become pitchers, and because competition (with the exception of university baseball) is in single-elimination tournaments, those aces throw game after game until their bodies break down. They are then surpassed by those who were a step behind them a year or two earlier.

Many of Japan’s best pitchers were not aces in elementary school or junior high. Masahiro Tanaka was a catcher until high school. Koji Uehara ran track in junior high and was an outfielder until his senior year in high school, when his school’s ace, Yoshinori Tateyama began to break down from injury.

It is not that much of a stretch, then, to see many of those players born from April to June as being at the end of their physical tethers by the time the pros call on them.

I know I’ve talked about this before

If we make a top-25 of players in NPB’s draft era, the best single draft round was the first round of the 1968 draft, Hall of Famers Hisashi Yamada, Koji Yamamoto, a player who has curiously been overlooked for the Hall, Michio Arito, and another who will eventually make it, Koichi Tabuchi.

The second best group are three from the Fab 4, the fourth round of the 1991 draft, Ichiro Suzuki, Tomoaki Kanemoto and Norihiro Nakamura.