Tomoya Ishiyama (石山 智也)
Tomoya Ishiyama became a Central League umpire in 2008. He worked the 2012 NPB All-Star Games, 2018 Japan Series, 2019 NPB All-Star Games and 2019 Premier 12.
Sources include Japanese Wikipedia
All logos are the trademark & property of their owners and not Sports Reference LLC. We present them here for purely educational purposes. Our reasoning for presenting offensive logos.
Logos were compiled by the amazing SportsLogos.net.
Copyright © 2000-2023 Sports Reference LLC. All rights reserved.
The SPORTS REFERENCE and STATHEAD trademarks are owned exclusively by Sports Reference LLC. Use without license or authorization is expressly prohibited.
Much of the play-by-play, game results, and transaction information both shown and used to create certain data sets was obtained free of charge from and is copyrighted by RetroSheet.
Win Expectancy, Run Expectancy, and Leverage Index calculations provided by Tom Tango of InsideTheBook.com, and co-author of The Book: Playing the Percentages in Baseball.
Total Zone Rating and initial framework for Wins above Replacement calculations provided by Sean Smith.
Full-year historical Major League statistics provided by Pete Palmer and Gary Gillette of Hidden Game Sports.
Some defensive statistics Copyright © Sports Info Solutions, 2010-2023.
Some high school data is courtesy David McWater.
Many historical player head shots courtesy of David Davis. Many thanks to him. All images are property the copyright holder and are displayed here for informational purposes only.
Data Provided By
the official stats partner of the NBA, NHL and MLB.
We're Social...for Statheads
Every Sports Reference Social Media Account
Site Last Updated:
Question, Comment, Feedback, or Correction?
Subscribe to our Free Email Newsletter
Subscribe to Stathead Baseball: Get your first month FREE
Your All-Access Ticket to the Baseball Reference Database
Do you have a sports website? Or write about sports? We have tools and resources that can help you use sports data. Find out more.