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XG's "best choice"

Posted By: Ray Kershaw
Date: Sunday, 26 July 2015, at 1:47 p.m.

When the correct cube action is no double / take, XG provides a "best choice" percentage. I interpret this as the probability that your opponent will pass which makes it correct to double. But I can't follow how XG calculates this.

For example,in this last roll position, with no Jacoby Rule, XG gives "best choice" as 19.0%. But I think this should be 23.5%. If I get a pass 23.5% of the time for a win of +1 and a take 76.5% of the time with an average loss of -0.889, then on average my loss after doubling is -0.444, the same equity as when I do not double.

Can one of the experts here explain where I go wrong?

	is Player 2 score: 0 pip: 1 Unlimited Game pip: 9 score: 0 is Player 1
XGID=----AA------------------a-:0:0:1:00:0:0:0:0:10
on roll, cube action?

Analyzed in XG Roller++	No double	Double/Take
Player Winning Chances:	27.78% (G:0.00% B:0.00%)	27.78% (G:0.00% B:0.00%)
Opponent Winning Chances:	72.22% (G:0.00% B:0.00%)	72.22% (G:0.00% B:0.00%)
Cubeless Equities	-0.444	-0.889
Cubeful Equities
No double:	-0.444
Double/Take:	-0.889 (-0.444)
Double/Pass:	+1.000 (+1.444)
Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 19.0%

eXtreme Gammon Version: 2.19.208.pre-release

Messages In This Thread

• XG's "best choice"
  Ray Kershaw -- Sunday, 26 July 2015, at 1:47 p.m.
  • XG's "best choice"
    Timothy Chow -- Sunday, 26 July 2015, at 5:20 p.m.
    • XG's "best choice"
      Ray Kershaw -- Sunday, 26 July 2015, at 9:35 p.m.
      • XG's "best choice"
        AdamStocks -- Monday, 27 July 2015, at 12:20 a.m.
        • XG's "best choice"
          AdamStocks -- Monday, 27 July 2015, at 2:16 a.m.
  • XG's "best choice"
    eXtreme Gammon -- Monday, 27 July 2015, at 2:12 a.m.