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Fair handicap question

Posted By: Ian Terry
Date: Thursday, 15 March 2018, at 9:58 p.m.

In Response To: Fair handicap question (Phil Simborg)

I estimated about 60% for #1 based on anecdotal evidence alone, but I figured math and a couple of formula would be helpful.

First, I converted PRs to Gridgammon rating using the empirical formula GGR = 2065-40*PR. This gave the 3.5 PR player a rating of 1925 and the 7 PR player a rating of 1785 (formula source: https://forumserver.twoplustwo.com/138/backgammon-forum-hosted-bill-robertie/pr-elo-grid-gammon-1554957/ -- NOTE: I can't find the original post on bgonline forums).

I then used those in the Elo formula that computes ratings for sites like Gridgammon found here: http://www.bkgm.com/faq/Ratings.html#rating_formula.

This calculation yielded an answer of 60.5% -- pretty in-line with what I'd originally guessed!

I would do the 2nd of two problems, but I'm short on time right now and a better player could probably breeze through it. Looking at an MET, 5a-7a for two equal players gives 63% to the player at 5a, so that's something to keep in mind given the answer to #1.

No clue how to even approach #3 and would really have to think about it.

Messages In This Thread

• Fair handicap question
  Phil Simborg -- Thursday, 15 March 2018, at 8:33 p.m.
  • Fair handicap question
    Joe Russell -- Thursday, 15 March 2018, at 9:02 p.m.
    • Correction
      Joe Russell -- Friday, 16 March 2018, at 1:44 a.m.
      • Conclusion
        Phil Simborg -- Friday, 16 March 2018, at 11:30 a.m.
        • Conclusion
          Tenland -- Friday, 16 March 2018, at 4:59 p.m.
          • i got it!!!!
            Phil Simborg -- Friday, 16 March 2018, at 8:48 p.m.
            • i got it!!!!
              jeom -- Saturday, 17 March 2018, at 10:55 a.m.
        • Conclusion
          Bob Koca -- Friday, 16 March 2018, at 5:38 p.m.
        • Conclusion
          Michael -- Friday, 16 March 2018, at 7:40 p.m.
  • Fair handicap question
    Ian Terry -- Thursday, 15 March 2018, at 9:58 p.m.
    • Fair handicap question
      Joe Russell -- Friday, 16 March 2018, at 1:55 a.m.
      • Fair handicap question
        Ian Terry -- Friday, 16 March 2018, at 3:14 a.m.
        • Fair handicap question
          Joe Russell -- Friday, 16 March 2018, at 7:53 a.m.
        • Fair handicap question
          Neil Robins -- Friday, 16 March 2018, at 3:35 p.m.
    • Fair handicap question
      AdamStocks -- Monday, 19 March 2018, at 1:35 a.m.
  • Fair handicap question
    Stick -- Friday, 16 March 2018, at 2:59 a.m.
    • Fair handicap question
      Joe Russell -- Friday, 16 March 2018, at 7:50 a.m.
      • Fair handicap question
        Stick -- Friday, 16 March 2018, at 11:36 a.m.
        • Fair handicap question
          Joe Russell -- Friday, 16 March 2018, at 9:33 p.m.
  • Fair handicap question
    Casper Van der Tak -- Friday, 16 March 2018, at 7:11 a.m.
  • Fair handicap question
    Michael -- Friday, 16 March 2018, at 3:59 p.m.
  • Fair handicap question
    Bob Koca -- Friday, 16 March 2018, at 5:34 p.m.