On this past week’s Japan Baseball Weekly Podcast, a listener asked:

1. Who had the single most dominant season in the Heisei era (1989 to April 30, 2019)?
2. Who was the best player of the Heisei era in NPB?

To recap our answers, we split on Question 1. John (@JBWPodcast) Gibson answered Masahiro Tanaka‘s 2013, 24-0 MVP season for the Rakuten Eagles, while I had Tetsuto Yamada‘s 2015 MVP season at second base for the Yakult Swallows, which ranks — according to Bill James’ win shares — as the seventh most valuable season in Japanese pro baseball history.

The Heisei Most Dominant Season Award

Tanaka’s season ranks 457th overall among all players in history, and second behind Hall of Famer Masaki Saito’s 1989 season for the Yomiuri Giants. But if one thinks about how the game has changed, Tanaka’s season is pretty darn remarkable.

The quality of play in NPB has increased steadily along with the number of pitches needed to get batters out. Saito, who is a big strong guy like Tanaka had a season that was a little better but required 33 more innings to accomplish.

In terms of how much Tanaka accomplished per inning pitched, his 2013 season is third in Japanese baseball history, behind two more Hall of Famers, Masaichi Kaneda (1958, Kokutetsu Swallows) and Tadashi Sugiura (1959, Nankai Hawks) during Japan’s most pitcher-friendly years since the end of World War II.

John, for those of you who haven’t heard it, brought up Wladimir Balentien‘s 60-home run 2013 season, but Win Shares has that ranked right behind Hotaka Yamakawa‘s MVP season last year for the Seibu Lions and the 28th most valuable during the Heisei era.

The Heisei MVP Award

John and I both picked Tomoaki Kanemoto as the Heisei MVP, which came as a shock to Mr. Gibson. The question excluded Ichiro Suzuki, but if I valued his MLB win shares at 1.2 per NPB WS, he ranks as the undisputed Heisei king. Through that somewhat conservative formula, Suzuki’s 540 ranks him third in Japanese baseball history, far behind the run-away leader, Sadaharu Oh (723 WS) and catcher Katsuya Nomura (581). Because the bulk of Suzuki’s win shares come from MLB, he would shoot past Nomura if each WS was valued at 1.5 per NPB win share.

If we allowed MLB win shares, Kanemoto would finish third, right behind Hideki Matsui.

Anyway, here are the top Heisei win share seasons:

Position players

Pitchers

And for the guy who doesn’t fit anywhere easily, Shohei Ohtani had 32.3 win shares in 2016 as a pitcher and a hitter, and would have ranked high in either list had he only batted or pitched.

You can find my post on NPB’s Heisei era pitching leaders HERE.