The Backgammon Galaxy calculator on this page is the Version 1 formula.
Backgammon Galaxy Version 1 Ratings Calculator
| Backgammon Galaxy Version 1 Ratings Calculator |
|
|
|
|
| Rating Changes if P1 Wins |
|---|
| Player 1: | |
| Player 2: | |
| Rating Changes if P2 Wins |
|---|
| Player 1: | |
| Player 2: | |
|
Instructions
1. Enter beginning-of-match (not end-of-match) ratings in the Ratings boxes. Note that the Backgammon Galaxy end-of-match screen shows end-of-match ratings, so for testing purposes, if you use this screen, you will have to back into the beginning-of-match ratings (calculate them by hand).
2. Enter the match length in the Match Length box.
3. Click the "Calculate" button.
Notes
1. The Version 1 ratings formula was in place from website startup to late July 2023 when Version 1 was discontinued.
2. This Version 1 calculator was written in early August 2020 and released on August 7, 2020. I verified it by examining dozens of match videos on YouTube and Facebook. Since then, other testers have also verified the formula based on their own matches (hundreds of matches).
3. The Backgammon Galaxy Version 2 formulas were effective from July 25, 2022 (iOS app release) to September 4, 2023. The Version 2 ratings formula changed on September 5, 2023. For the new Version 2 ratings formula, see the main Ratings page.
5. For the old Version 2 (July 25, 2022 to September 4, 2023) ratings formula, use the Version 1 web calculator or the relevant Excel files (links below). In the (old) Version 2, if one player wins both the match and the PR, the rating changes are as noted in the Version 1 web calculator. If the match winner is different than the PR winner, the match winner will gain half the rating change noted in the Version 1 calculator and the match loser will lose half the rating change noted in the Version 1 calculator. When I have time (mid-October 2023), I'll write a proper "old" Version 2 web calculator. Note that the relevant Excel files (links below) currently have this old Version 2 calculator.
Full Backgammon Galaxy Version 1 ratings formula explanation
Credits
The Backgammon Galaxy Version 1 rating formula was written in August 2020 and released on August 7, 2020.
The Backgammon Galaxy formulas were researched and written by Chris Yep.
Excel calculators/files author: Chris Yep
Web calculators coding: Chris Yep and Jason Marshall
Excel files (calculators)
Old Backgammon Galaxy calculators
All ratings calculators (both old and new) in one file
If you notice any errors, please contact Chris Yep.
Full Backgammon Galaxy Version 1 ratings formula explanation