FIBS Board backgammon forum

Backgammon => Fibsboard Forum Matches => FFM 7 => Topic started by: ah_clem on November 05, 2010, 11:48:21 AM

Poll
Question: Double deuces to play

Option 1: 13/7 9/7 votes: 7
Option 2: 13/9(2) votes: 0
Option 3: 13/9 13/11(2) votes: 0
Option 4: 13/9 13/11 6/4 votes: 0
Title: Game 3 move 10 The Herd to play2-2
Post by: ah_clem on November 05, 2010, 11:48:21 AM
We have a 2-2 to play. 

This poll will run through Sunday unless a)we decide on a move in the next couple of hours or b) some other mod steps in to move it along.  the .sgf file is attached.
Title: Re: Game 3 move 10 The Herd to play2-2
Post by: ah_clem on November 05, 2010, 12:04:20 PM
Spoiler

Making the bar point is the "obvious" play. I almost nexted it.  But what about making the nine instead?  The bar point forms a much better blockade, but we'll be up by nearly 40 pips after this move, so we don't really want a blockade.  Holding a point 7 pips away form the anchor makes it very easy to clear since we can leave a single checker there without leaving a direct shot. Making the nine gives us the chance to make the five point with a 4-1 (either play allows us to make it with a 22 or 44).  But 6-4 plays awkwardly if we make the nine.

I'm going to go with the "obvious" play, even though it's far from obvious that it's best - making the nine has much to be said for it,  I just haven't convinced myself that it's better.  Perhaps someone else can convince me.

13/7 9/7

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Title: Re: Game 3 move 10 The Herd to play2-2
Post by: NIHILIST on November 05, 2010, 01:55:16 PM
Spoiler
You may not want a blockade but you gotta love having the bar point as a landing spot.
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Bob
Title: Re: Game 3 move 10 The Herd to play2-2
Post by: ah_clem on November 05, 2010, 02:17:19 PM
Spoiler
Quote from: NIHILIST on November 05, 2010, 01:55:16 PM
You may not want a blockade but you gotta love having the bar point as a landing spot.

Owning the bar point also blocks some indirect shots in the outfield, so the blockade does more than just keep him from running. The solid formation has to be better. I'm convinced now.

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Title: Re: Game 3 move 10 The Herd to play2-2
Post by: ah_clem on November 05, 2010, 04:25:58 PM
It's 7-0.  Let's move on.
Title: Re: Game 3 move 10 The Herd to play2-2
Post by: ah_clem on November 08, 2010, 01:47:47 PM
rollout


Spoiler


Making the nine is not a serious error, but making the seven is definitely better.


    1. Rollout          13/7 9/7                     Eq.:  +0.312
       0.712 0.076 0.005 - 0.288 0.033 0.001 CL  +0.434 CF  +0.312
      [0.001 0.002 0.001 - 0.001 0.001 0.000 CL   0.004 CF   0.005]

    2. Rollout          13/9(2)                      Eq.:  +0.280 ( -0.031)
       0.695 0.084 0.006 - 0.305 0.037 0.001 CL  +0.399 CF  +0.280
      [0.001 0.002 0.001 - 0.001 0.001 0.000 CL   0.004 CF   0.005]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 905729009 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]


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