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Prime-rolling technique

Posted By: Nack Ballard
Date: Saturday, 23 February 2019, at 5:16 p.m.

In Response To: XG RO (Casper Van der Tak)

It depends on distribution. Starting with the ugly checker on the 4pt is much of the reason that hitting with the 3 is best in the original position. That is why I moved it back to the 6pt and changed the roll to 65 here, so that it is possible to roll the prime forward without committing a spare to the 4pt.

Below is that rollout again (but 4-ply, as I'm short on time today), this time with White's checkers all stacked on the 1pt:

		White is Player 2 score: 0 pip: 31 7 point match pip: 89 score: 0 Blue is Player 1
XGID=-aAABBCBBB--------------g-:0:0:1:65:0:0:0:7:10
No chance to pick up a second checker

1.	Rollout1	8/3 8/2	eq: +0.274
	Player: Opponent: 57.18% (G:0.00% B:0.00%) 42.82% (G:0.40% B:0.01%) Conf.: ± 0.003 (+0.271...+0.277) - [70.9%] Duration: 1 minute 09 seconds
2.	Rollout1	9/3 6/1*	eq: +0.273 (-0.001)
	Player: Opponent: 57.24% (G:0.00% B:0.00%) 42.76% (G:0.57% B:0.01%) Conf.: ± 0.003 (+0.270...+0.276) - [29.1%] Duration: 1 minute 33 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 77188237 Moves and cube decisions: 4-ply

[Naturally, 9/4 9/3 comes in third -- just as 9/6 9/3 would come in third in Highlander's original 63 position even if White's checkers are all on the 1pt -- because it puts/keeps a checker on the 4pt (too advanced.)]

However, even that situation is biased, because one or both of the semi-advanced 9pt checkers might be forced as low as the 4pt or even the 3pt.

To further isolate the prime-rolling decision, let's move one of the 9pt checkers into the back quadrant. Blue's position is more fluid, and hitting on the 1pt (before making the 2pt) becomes a noticeable error:

		White is Player 2 score: 0 pip: 31 7 point match pip: 103 score: 0 Blue is Player 1
XGID=-aAABBCBBA-------------Ag-:0:0:1:65:0:0:0:7:10
Fluid choice

1.	Rollout1	8/3 8/2	eq: +0.326
	Player: Opponent: 58.91% (G:0.00% B:0.00%) 41.09% (G:0.05% B:0.00%) Conf.: ± 0.003 (+0.323...+0.329) - [100.0%] Duration: 35.9 seconds
2.	Rollout1	9/3 6/1*	eq: +0.307 (-0.019)
	Player: Opponent: 58.19% (G:0.00% B:0.00%) 41.81% (G:0.32% B:0.01%) Conf.: ± 0.003 (+0.304...+0.310) - [0.0%] Duration: 56.9 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 36223632 Moves and cube decisions: 4-ply

In case that seems like sleight of hand, here's a rollout that more simply compares covering the 2pt vs hitting on the 1pt:

		White is Player 2 score: 0 pip: 31 Unlimited Game Jacoby Beaver pip: 100 score: 0 Blue is Player 1
XGID=-aABBBBCB---------------gA:0:0:1:62:0:0:3:0:10
Simple 6 comparison

1.	Rollout1	Bar/23 8/2	eq: +0.314
	Player: Opponent: 58.50% (G:0.00% B:0.00%) 41.50% (G:0.09% B:0.00%) Conf.: ± 0.004 (+0.310...+0.317) - [100.0%] Duration: 43.9 seconds
2.	Rollout1	Bar/23 7/1*	eq: +0.301 (-0.012)
	Player: Opponent: 58.16% (G:0.00% B:0.00%) 41.84% (G:0.36% B:0.01%) Conf.: ± 0.004 (+0.298...+0.305) - [0.0%] Duration: 1 minute 06 seconds
1 5184 Games rolled with Variance Reduction. Dice Seed: 77188237 Moves and cube decisions: 4-ply

Hope that helps.

Nack

Messages In This Thread

• Newbie prime rolling question
  highlander -- Friday, 22 February 2019, at 2:55 a.m.
  • Newbie prime rolling question
    Casper Van der Tak -- Friday, 22 February 2019, at 7:08 a.m.
    • XG RO
      neilkaz -- Friday, 22 February 2019, at 9:57 p.m.
      • XG RO
        hominid -- Saturday, 23 February 2019, at 3:03 a.m.
        • XG RO
          neilkaz -- Saturday, 23 February 2019, at 3:25 a.m.
          • XG RO
            Casper Van der Tak -- Saturday, 23 February 2019, at 1:27 p.m.
            • Prime-rolling technique
              Nack Ballard -- Saturday, 23 February 2019, at 5:16 p.m.
              • Prime-rolling technique *NM*
                Nack Ballard -- Saturday, 23 February 2019, at 5:19 p.m.
              • Prime-rolling technique
                Casper Van der Tak -- Sunday, 24 February 2019, at 4:12 a.m.
                • Prime-rolling technique
                  Casper Van der Tak -- Sunday, 24 February 2019, at 4:15 a.m.
  • Newbie prime rolling question -- ++ ROLLOUTS with third play added
    Nack Ballard -- Saturday, 23 February 2019, at 2:36 a.m.
  • Newbie prime rolling question
    highlander -- Saturday, 23 February 2019, at 4:47 a.m.