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Backgammon => Fibsboard Forum Matches => FFM 15 => Topic started by: diane on May 14, 2013, 09:27:21 PM

Poll
Question: Move
Option 1: 24/22, 13/8 votes: 1
Option 2: 9/4*, 6/4 votes: 6
Option 3: 13/6 votes: 0
Option 4: 24/22, 6/1 votes: 0
Option 5: 13/8, 6/4* votes: 1
Title: Game 5, move 4 : Herd 5-2
Post by: diane on May 14, 2013, 09:27:21 PM
move?
Title: Re: Game 5, move 4 : Herd 5-2
Post by: ah_clem on May 15, 2013, 12:32:43 AM
Spoiler
Tough play.

My initial instinct was to make the 4 point, but that breaks the 4 prime, and leaves 10 fly shots from the bar.  We don't want to get gammoned here, so I'm playing chicken with 24/22 13/8.

No confidence in it though.
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Title: Re: Game 5, move 4 : Herd 5-2
Post by: KDP on May 15, 2013, 12:56:47 AM
Spoiler
lets look at the candidate plays:24-22 6-1 i think we can eliminate right off.  i cant see burying a checker on the ace as being correct.  13-6 also looks wrong as we dont need or want to stack another checker on the 6 so that one is also out for me.  13-8 24-22 brings another builder down and moves our straggler up some so that is an OK move but still a little passive, to that leaves the 2 hitting plays.  9-4*-6-4 hitting and making a point but leaving some return shots or 13-8 6-4* hitting loose.  im more inclined to make the 4 and take my chances on the return than hitting loose.  if i was playing doubles and my partner was neilkaz or stick and he said hit loose i'd go with that, if my partner is joe blow i'd argue for hitting and making the point.  i dont think there is going to be a huge difference between the two however.  9-4 6-4* thats my final answer.
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Title: Re: Game 5, move 4 : Herd 5-2
Post by: ah_clem on May 15, 2013, 01:30:06 PM
Spoiler

Thinking about it some more and reading other responses, I've come to agree with the Herd.  The chicken play accomplishes little - another builder is fine, but moving the runner up undermines it's position - it needs to get to the edge of the prime to leap out, and by creeping closer there are fewer rolls that allow it to step up.

There are only 10 fly shots after pointing on his head, and we have a good chance to cover the 9.  And the 6 desperately needs to be unstacked.

9/4* 6/4.
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Title: Re: Game 5, move 4 : Herd 5-2
Post by: ah_clem on May 16, 2013, 03:10:24 AM

XGR++

Spoiler


The Herd's play is best by about .05 according to XGR++.  This is sufficiently non-close that a full rollout isn't necessary, although a full rollout would be necessary to settle 2nd place - the chicken play and the hyper-aggressive play are statistically tied.

XGID=----abEBBB--aC--bbbcb---A-:0:0:1:52:4:1:1:5:10

X:Player 1   O:Player 2
Score is X:4 O:1 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X        O  O  O |   | O  O           X |
| X        O  O  O |   | O  O             |
| X                |   | O                |
|                  |   |                  |
|                  |   |                  |
|                  |BAR|                  |
|                  |   | X                |
|                  |   | X                |
|                  |   | X                |
|          X  X  X |   | X  O             |
| O        X  X  X |   | X  O  O          |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 141  O: 150 X-O: 4-1/5 Crawford
Cube: 1
X to play 52

    1. XG Roller++ 9/4* 6/4                     eq:-0.370
      Player:   38.43% (G:10.11% B:0.44%)
      Opponent: 61.57% (G:13.52% B:0.48%)

    2. XG Roller++ 24/22 13/8                   eq:-0.417 (-0.047)
      Player:   36.32% (G:7.92% B:0.31%)
      Opponent: 63.68% (G:14.00% B:0.39%)

    3. XG Roller++ 13/8 6/4*                    eq:-0.419 (-0.049)
      Player:   36.81% (G:8.36% B:0.38%)
      Opponent: 63.19% (G:15.13% B:0.58%)

    4. 3-ply       24/22 6/1                    eq:-0.437 (-0.067)
      Player:   36.62% (G:7.63% B:0.26%)
      Opponent: 63.38% (G:16.48% B:0.52%)

    5. 3-ply       13/6                         eq:-0.444 (-0.073)
      Player:   34.66% (G:6.92% B:0.25%)
      Opponent: 65.34% (G:13.33% B:0.48%)


eXtreme Gammon Version: 2.10, MET: Kazaross XG2
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