BGonline.org Forums

21\$ 63 oddity

Posted By: David Rockwell
Date: Monday, 4 August 2014, at 3:37 a.m.

In Response To: 21\$ 63 oddity (Bob Koca)

Play is different at different scores. It doesn't work to apply different gammon values to the gammon wins and losses to predict results at different scores. Note also that GG and GS don't have cubes while unlimited play does. We know that efficient cubes are the reason that an opening 21S is correct at some scores.

Look at 53P-21. The money play of 21S isn't correct at ANY score in a four point match. 21\$ is always correct. And most of the time, it is correct by a lot. 21S is a material error. For example 53P-21 3a3a[\$ S27] "<5 (shown below).

Also check out:

61P-41

61P-51

52D-62

64P-52

32S-62

21\$-62

62R-31

And there are many others for which the money play isn't best at many or most scores in a five point match.

 White is Player 2 score: 0 pip: 159 3 point match pip: 167 score: 0 Blue is Player 1
XGID=-b----E-C---eE---b-d--b-B-:0:0:1:21:0:0:0:3:10
Blue to play 21

1.Rollout113/11 6/5eq: -0.2066
 Player:Opponent: 46.47% (G:12.56% B:0.96%)53.53% (G:19.05% B:3.20%) Conf.: ±0.0093 (-0.2159...-0.1973) - [100.0%]Duration: 1 hour 17 minutes
2.Rollout124/23 13/11eq: -0.2335 (-0.0268)
 Player:Opponent: 45.96% (G:12.39% B:0.94%)54.04% (G:18.35% B:1.74%) Conf.: ±0.0082 (-0.2417...-0.2252) - [0.0%]Duration: 1 hour 09 minutes
1 5184 Games rolled with Variance Reduction.
Dice Seed: 96654469
Moves and cube decisions: 3-ply

eXtreme Gammon Version: 2.10, MET: Rockwell-Kazaross

• 21\$ 63 oddity
Bob Koca -- Monday, 4 August 2014, at 2:44 a.m.
• 21\$ 63 oddity
David Rockwell -- Monday, 4 August 2014, at 3:37 a.m.

Post Response

Subject:
Message: