Baseball Player Won-Lost Records

An overview of the website can be found here. A brief (six-minute) video explanation of why I created Player won-lost records can be found here.

The basic calculation of Player won-lost records is described here. A somewhat lengthy (53-page PDF) discussion of comparing players using Player won-lost records, focusing on positional averages is here. Recent changes to Player won-lost records which were made in July and August of 2019 are described here. Player won-lost records are compared to WAR (as calculated by Baseball-Reference and Fangraphs) in an article here.

For a more in-depth description of Player won-lost records, how they are calculated, and who the best players of the past 80 years were in various aspects of Player won-lost records, I have published a book with McFarland, entitled Player Won-Lost Records in Baseball: Measuring Performance in Context.

I have self-published two additional books, which are available as free PDF downloads on my website, or for purchase in either paperback or Kindle format at Amazon. See here for more details.

I gave a presentation to the Chicago chapter of SABR (Society for American Baseball Research) on November 18, 2017. I have posted video of the presentation and follow-up Q-and-A on YouTube. The video runs almost exactly one hour. I also have a couple of shorter (5-10 minute) videos up on YouTube as well: see here.

Thank you for visiting the site and please come back often!

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note: Player Won-Lost records are estimated for all seasons from 1916 to 2018, and a handful of earlier seasons.

Data for 2017 are preliminary.

The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at "".
Baseball player won-lost records have been constructed by Tom Thress. Feel free to contact me by e-mail, follow me on Twitter, and/or subscribe to my YouTube channel.