A screwballer, Yamamoto pitched for the Chunichi Dragons in Japan's Nippon Professional Baseball for 29 years from 1986 to 2015.

Yamamoto attended Nichidai Fujisawa High School, and was selected at age 18 by Chunichi.

On September 16, 2006, Yamamoto threw a no-hitter against the Hanshin Tigers, becoming the oldest pitcher in NPB to throw a no-hit game.

On September 5, 2014, Yamamoto won his first and only start of the season at Nagoya Dome in a shutout match against the Hanshin Tigers, making him the oldest Japanese pitcher to win a game, at 49 years, 25 days, surpassing the old mark of 48 years, 4 months set by the Hankyu Braves’ Shinji Hamazaki in 1950.

[4] In addition, Yamamoto also has owned shares of racehorses, with his most successful horses being Al Ain and Shahryar.