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Which one to clear? ** Rollout **

Posted By: Taper_Mike
Date: Wednesday, 27 July 2011, at 7:33 p.m.

In Response To: Which one to clear? (bayblitz)

This problem lends itself to counting.

After playing inside, 4/1, 3/1, Blue will be forced to expose a blot after rolling 61, 62, 51, or 41. In addition, Blue may be forced to leave two blots when he rolls 64. (It depends whether White has run off Blue's 5 point). If Blue plays inside with 4/1, 4/2, you can add 31 to the list of rolls that force single exposure.

There is also a “pay-later” aspect to playing inside. Suppose that Blue can clear his 9 point and comes down to a position with 2 checkers on the 6 point. Rolling 61 or 51 (and, depending the position, perhaps even 41) will cause Blue to leave another shot. If, instead, Blue gets down to three checkers on the 6 point, things are even worse, for then he must face the risk of rolling 65 before he gets down to 2 checkers.

There is a seeming advantage to holding the 6 point: it gives a landing place for checkers coming off the 9 point. Rolls with a 3, in particular, 63 and 53, become clearing rolls. If Blue cares to, he can take the same risks he faced on this toss again, by choosing to keep the status quo. But in that circumstance, he will sometimes be forced off the 6 point anyway, before he can clear the 9 point. It happens when he rolls 52, 54, 42, 43, or 44. That adds up to 9 rolls out of 36. It’s a loser. By holding the 6-point, in 25% of the cases, Blue will have gratuitously undertaken all the risks listed in the second paragraph above.

After clearing the 6 point, on the other hand, Blue will be leave a blot when he rolls 61, 62, 63, 64, 51, 52, 53, 54, 41, 42, or 43. That is 22 shots, but there are no gratuitous risks, no “pay-later” price as regards the 6 point, and no double blots. A point cleared is a point cleared.

Mike

		White is Player 2 score: 0 pip: 85 3 point match pip: 55 score: 0 Blue is Player 1
XGID=-CDBBbB--B--------abb-cbc-:1:-1:1:32:0:0:0:3:10
Blue to play 32

1.	Rollout1	6/4 6/3	eq: +0.541
	Player: Opponent: 81.39% (G:1.00% B:0.01%) 18.61% (G:0.20% B:0.00%) Conf.: ± 0.003 (+0.538...+0.543) - [100.0%] Duration: 22.3 seconds
2.	Rollout1	4/2 4/1	eq: +0.513 (-0.028)
	Player: Opponent: 79.93% (G:0.67% B:0.03%) 20.07% (G:0.65% B:0.01%) Conf.: ± 0.003 (+0.510...+0.516) - [0.0%] Duration: 32.1 seconds
3.	Rollout1	4/1 3/1	eq: +0.459 (-0.082)
	Player: Opponent: 77.31% (G:0.87% B:0.01%) 22.69% (G:0.96% B:0.02%) Conf.: ± 0.003 (+0.456...+0.461) - [0.0%] Duration: 32.2 seconds
4.	XG Roller++	9/7 9/6	eq: +0.435 (-0.106)
	Player: Opponent: 77.57% (G:1.60% B:0.01%) 22.43% (G:0.27% B:0.00%)
5.	2-ply	9/4	eq: +0.276 (-0.265)
	Player: Opponent: 70.03% (G:2.12% B:0.01%) 29.97% (G:0.56% B:0.01%)
1 1296 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.00, MET: Kazaross XG2

Messages In This Thread

• Which one to clear?
  bayblitz -- Friday, 22 July 2011, at 8:41 a.m.
  • Which one to clear?
    Turz -- Friday, 22 July 2011, at 9:40 a.m.
    • Which one to clear?
      bayblitz -- Friday, 22 July 2011, at 10:40 a.m.
      • Which one to clear?
        Casper van der Tak -- Friday, 22 July 2011, at 10:51 a.m.
  • Which one to clear?
    Carlo Melzi -- Friday, 22 July 2011, at 11:10 a.m.
  • Which one to clear? ** Rollout **
    Taper_Mike -- Wednesday, 27 July 2011, at 7:33 p.m.