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That old chestnut, 51S-21

Posted By: David Rockwell
Date: Monday, 15 August 2016, at 7:07 p.m.

In Response To: That old chestnut, 51S-21 (Timothy Chow)

As far as opening rollouts go, this is a large margin. So to my knowledge, it hasn't been rolled deeper. Based on the data I have seen, using parameters that are a little stronger aren't going to reverse this. You would have to use very strong parameters like ++ for cube and move to have a CHANCE that this would switch. If you feel like playing 21$ for fun, I recommend it despite the rollout.

But, match players have many chances to play it when it is correct in a match. You don't even have to be trailing. 51S-21$ is correct at all trailing scores I have seen along with DMP, 3a3a and 4a4a. (It is unusual that 3a3a matches the 4a4a play and 5a5a doesn't. I don't know why this happened.) Slotting may also be correct at odd-Crawford scores when leading, I'm not sure.

		White is Player 2 score: 0 pip: 161 3 point match pip: 167 score: 0 Blue is Player 1
XGID=-aa---E-C---dE---d-e----B-:0:0:1:21:0:0:0:3:10
Blue to play 21

1.	Rollout1	13/11 6/5	eq: -0.1778
	Player: Opponent: 46.76% (G:12.33% B:0.97%) 53.24% (G:17.54% B:2.65%) Conf.: ±0.0028 (-0.1807...-0.1750) - [100.0%] Duration: 11 hours 52 minutes
2.	Rollout1	24/21	eq: -0.1894 (-0.0116)
	Player: Opponent: 46.43% (G:11.23% B:0.90%) 53.57% (G:15.36% B:1.30%) Conf.: ±0.0024 (-0.1918...-0.1871) - [0.0%] Duration: 10 hours 07 minutes
3.	Rollout2	13/10	eq: -0.2048 (-0.0270)
	Player: Opponent: 45.87% (G:12.31% B:0.92%) 54.13% (G:16.17% B:1.86%) Conf.: ±0.0035 (-0.2083...-0.2013) - [0.0%] Duration: 5 hours 55 minutes
4.	Rollout3	24/23 13/11	eq: -0.2117 (-0.0339)
	Player: Opponent: 45.91% (G:11.71% B:0.87%) 54.09% (G:16.22% B:1.40%) Conf.: ±0.0047 (-0.2164...-0.2070) - [0.0%] Duration: 3 hours 12 minutes
1 62208 Games rolled with Variance Reduction. Dice Seed: 57020913 Moves and cube decisions: 3-ply 2 31104 Games rolled with Variance Reduction. Dice Seed: 57020913 Moves and cube decisions: 3-ply 3 15552 Games rolled with Variance Reduction. Dice Seed: 57020913 Moves and cube decisions: 3-ply

eXtreme Gammon Version: 2.10, MET: Rockwell-Kazaross

Messages In This Thread

• That old chestnut, 51S-21
  Timothy Chow -- Monday, 15 August 2016, at 5:25 p.m.
  • That old chestnut, 51S-21
    David Rockwell -- Monday, 15 August 2016, at 7:07 p.m.
    • That old chestnut, 51S-21
      neilkaz -- Monday, 15 August 2016, at 11:12 p.m.
      • That old chestnut, 51S-21
        David Rockwell -- Tuesday, 16 August 2016, at 1:34 a.m.
        • That old chestnut, 51S-21
          neilkaz -- Tuesday, 16 August 2016, at 3:43 a.m.
  • 51S-21 – Unlimited with Jacoby – XG2 3-ply Rollout
    Taper_Mike -- Monday, 15 August 2016, at 7:28 p.m.
  • 51S-21 – Index to Rollouts
    Taper_Mike -- Sunday, 21 August 2016, at 7:54 p.m.