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Pick Your Poison — Rollout & Analysis

Posted By: Taper_Mike
Date: Saturday, 21 July 2012, at 8:34 a.m.

In Response To: Pick Your Poison (Taper_Mike)

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		White is Player 2 score: 0 pip: 116 Unlimited Game Jacoby Beaver pip: 71 score: 0 Blue is Player 1
XGID=-ACbD-CBB---aa----abbbbb--:1:-1:1:11:0:0:3:0:10
Blue to play 11

1.	Rollout1	8/7 8/6 2/1	eq: +0.6241
	Player: Opponent: 81.85% (G:3.48% B:0.02%) 18.15% (G:0.74% B:0.02%) Conf.: ±0.0009 (+0.6232...+0.6251) - [100.0%] Duration: 26 minutes 12 seconds
2.	Rollout1	8/6(2)	eq: +0.6217 (-0.0024)
	Player: Opponent: 81.49% (G:4.23% B:0.02%) 18.51% (G:0.94% B:0.04%) Conf.: ±0.0009 (+0.6209...+0.6226) - [0.0%] Duration: 29 minutes 22 seconds
3.	Rollout1	7/5(2)	eq: +0.6183 (-0.0058)
	Player: Opponent: 81.35% (G:4.34% B:0.03%) 18.65% (G:1.32% B:0.04%) Conf.: ±0.0009 (+0.6175...+0.6192) - [0.0%] Duration: 30 minutes 06 seconds
1 20736 Games rolled with Variance Reduction. Dice Seed: 90430824 Moves: 3-ply, cube decisions: XG Roller

Rollout by Taper_Mike 2012-Jul-20 eXtreme Gammon Version: 2.03 Flashcard PositionID 000645.xgp

eXtreme Gammon Version: 2.03

Without much thought, I grabbed the checkers on the 7pt, and filled the gap on the 5pt. Later, I was surprised to discover that move is 3rd best! The best play picks up the 8pt, but leaves 3 checkers on bar point. It’s a move that grates against most of our instincts. Usually, when you add a third checker to an outside point you are trying to clear, it makes the bear-in more difficult. The third checker must be moved on the following turn, and with it, often a spare in the inner board. Two turns later, you are down to 2 checkers outside, but have sacrificed the flexibility offerred by the spare. Often there is some kind double jeapardy involved. That is, with 3 checkers stacked outside, some rolls may force a blot. Later, when you get down to 2 checkers outside, your checkers are in jeapardy a second time. That is one of the things that makes this situation unusual. There is no double jeapardy. Stacking 3 checkers outside guarantees 100% safety on the next roll. This position is best categorized as pay-now-or-pay-later. And as the final two diagrams below demonstrate, the price you pay later is not that much worse the price offerred now. So, duck! By paying later, you may not have to pay at all.

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Blue played 8/6(2)

After Playing 8/6(2) 5 rolls leave a shot on the next turn: 64 62 44. 17 rolls clear an outside point safely on the next turn: 66 65 63 61 55 53 51 33 31 22 11. 14 rolls do neither: 54 52 43 42 41 32 21.

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Blue played 7/5(2)

After Playing 7/5(2) 7 rolls leave a shot on the next turn: 66 65 61 54. 16 rolls clear an outside point on the next turn: 64 63 62 44 43 42 33 32 22 11. 13 rolls do neither: 55 53 52 51 41 31 21.

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Blue played 8/7, 8/6, 2/1

After Playing 8/7, 8/6, 2/1 0 rolls leave a shot on the next turn. 6 rolls clear an outside point on the next turn: 66 55 44 33 22 11. 30 rolls do neither: 65 64 63 62 61 54 53 52 51 43 42 41 32 31 21.

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Blue is even on two highest points.

After Blue moves 8/7, 8/6, 2/1, White plays 53, and Blue plays 53 Blue is even on the highest two points. 4 rolls leave a shot on the next turn: 64 62. 17 rolls clear an outside point on the next turn: 66 65 63 61 55 53 51 33 31 22 11. 15 rolls do neither: 54 52 44 43 42 41 32 21.

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Blue is odd on the two highest points.

After Blue moves 8/7, 8/6, 2/1, White plays 53, and Blue plays 64 Blue is odd on the highest two points. 8 rolls leave a shot on the next turn: 66 64 62 55 54. 15 rolls clear an outside point on the next turn: 65 63 61 53 51 33 31 22 11. 13 rolls do neither: 52 44 43 42 41 32 21.

Mike

Messages In This Thread

• Pick Your Poison
  Taper_Mike -- Thursday, 19 July 2012, at 7:34 p.m.
  • Pick Your Poison
    Dmitriy Obukhov -- Thursday, 19 July 2012, at 11:52 p.m.
  • Pick Your Poison
    ah_clem -- Friday, 20 July 2012, at 1:58 p.m.
  • Pick Your Poison
    Timothy Chow -- Friday, 20 July 2012, at 10:48 p.m.
  • Pick Your Poison — Rollout & Analysis
    Taper_Mike -- Saturday, 21 July 2012, at 8:34 a.m.
    • Pick Your Poison — Rollout & Analysis
      Timothy Chow -- Saturday, 21 July 2012, at 4:45 p.m.