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Doubling problem

Posted By: Matt Cohn-Geier
Date: Saturday, 20 October 2007, at 5:03 a.m.

In Response To: Doubling problem (Dave)

If you take gammons completely out of the equation then my chances for winning the match were 25% if I passed vs. the 34% if I took the cube. Clear take. But since gammons do matter how does that affect that 25%? Or can that even be figured out? To further complicate matters, since I would be playing more aggressively for the gammon and increasing my gammon chances this should also mean that I'm decreasing my chances to win the single point game, so how does all that figure in?

One thing is clear: the trailer has significantly better equity than 25% at 2-away Crawford. He has very slightly worse than 25% at 3-away Crawford, because there he really does need to win two games, sometimes can win a backgammon, but his opponent usually gets a free drop.

In order to determine your equity (i.e., derive a match equity table), you would need to know how many gammons you won at 2-away Crawford. That number is very difficult to derive. Historically, METs tended to give about a 29-30% takepoint pre-bot. Bot rollouts pushed it up to ~32%. Why the discrepancy? Players of old weren't playing aggressively enough for the gammon. Balancing the risks of winning a gammon with potentially losing the game is difficult.

A player's Gammon Value is at 2-away Crawford is 1.0. I.e., he is willing to trade 1 gammon for 1 win, because a gammon wins him the match. So his ME from 2-away Crawford is equal to wins plus gammons, which presumably is somewhere around 24% wins and 8% gammons.

Messages In This Thread

• Doubling problem
  Dave -- Friday, 19 October 2007, at 1:45 p.m.
  • Doubling problem
    DC-Ohio -- Friday, 19 October 2007, at 3:01 p.m.
    • Doubling problem
      Dave -- Friday, 19 October 2007, at 3:33 p.m.
      • Doubling problem
        Chuck Bower -- Friday, 19 October 2007, at 5:05 p.m.
      • Doubling problem
        Matt Cohn-Geier -- Saturday, 20 October 2007, at 2:41 a.m.
        • Correction
          Matt Cohn-Geier -- Saturday, 20 October 2007, at 2:43 a.m.
        • Doubling problem
          Dave -- Saturday, 20 October 2007, at 3:44 a.m.
          • Doubling problem
            Matt Cohn-Geier -- Saturday, 20 October 2007, at 5:03 a.m.
  • Doubling problem
    Daniel Murphy -- Friday, 19 October 2007, at 3:06 p.m.
    • Doubling problem
      Dave -- Friday, 19 October 2007, at 4:11 p.m.
      • Doubling problem
        Daniel Murphy -- Friday, 19 October 2007, at 4:27 p.m.
        • Doubling problem
          Dave -- Friday, 19 October 2007, at 4:43 p.m.
          • Doubling problem
            Daniel Murphy -- Friday, 19 October 2007, at 5:21 p.m.
  • Doubling problem
    bob koca -- Saturday, 20 October 2007, at 12:23 a.m.
    • Doubling problem
      Dave -- Saturday, 20 October 2007, at 1:42 a.m.