FIBS Board backgammon forum

Backgammon => Fibsboard Forum Matches => FFM4 => Topic started by: ah_clem on December 30, 2009, 01:49:26 AM

Poll
Question: 5-1 to play
Option 1: bar/20 11/10 votes: 2
Option 2: bar/20 8/7 votes: 0
Option 3: bar/20 6/5 votes: 3
Option 4: bar/20 24/23 votes: 1
Option 5: bar/24 13/8 votes: 1
Option 6: bar/24 8/3 votes: 0
Option 7: bar/24 11/6 votes: 0
Title: Game 1 Move 1.5 Forum to play 5-1
Post by: ah_clem on December 30, 2009, 01:49:26 AM
Blitzxz rolled a  6-1 which I nexted - pointing on the head of the blot on the bar point is pretty obvious.
Now we have 5-1 to play from the bar.
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: ah_clem on December 30, 2009, 02:56:28 AM
Spoiler

Entering on the 24 seems too passive, so I'd opt to enter on the 20.  That leaves a one to play - moving 24/23 doesn't accomplish anything and leaves that blot utg.  Slotting the bar or five seems too risky.  That leaves the prosaic 11/10.

So it's bar/20 11/10 for me.

That said, I often screw up positions like these, so I'm all ears for a better analysis.



[close]
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: PersianLord on December 30, 2009, 06:48:08 AM
Spoiler
I would play bar/20-24/23. I see no reason why to move 11/10 which gives blitzxz two other shots to hit our blot. Besides, In case of a double 5s, he'd have an easier task with our last man at 24 pts (pointing on our head and unstacking his 6 pt) than when it's on the 23 pt.

Regards
[close]
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: dorbel on December 30, 2009, 10:04:04 AM
Spoiler
Entering on the 24pt is indeed too passive, so bar/20 is good. 24/23 and 11/10 both have their merits, but I like to play 6/5 here! It slots both the points that we want and unstacks the 6pt, both thematic in the opening. If ever there is a time for 4 blots, it's right at the start of the game. I would like to say that I have in some way reasoned my way towards this play, but actually it is one of a class of positions that I have researched in the past, so I know how well the double slot does! The other plays are equally good though.
[close]
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: ah_clem on December 30, 2009, 09:25:51 PM
The vote is close, so I'm going to let it run the full 24 hours before calling it. 

Spoiler


Looking at it again, I can see the advantages of slotting both 5 points, and my assessment of "too risky" is off the mark.  Slotting both fives is a sound play; for one thing you almost always manage to make one of the two points, so it's not risky at all.  That said, I'm not going to change my vote just yet, but I'll happily go along with bar/20 6/5 if it wins the vote..

[close]
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: ah_clem on December 31, 2009, 01:33:48 PM
The rollout doesn't give anything away, so here it is: 

Spoiler


Entering on the 5 is correct.  After that, moving the backman is best, slotting is fairly close and 11/10 is marginal.




    1. Rollout          bar/20 24/23                 Eq.:  -0.228
       0.453 0.108 0.005 - 0.547 0.155 0.007 CL  -0.152 CF  -0.228
      [0.002 0.002 0.001 - 0.002 0.002 0.001 CL   0.006 CF   0.014]

    2. Rollout          bar/20 6/5                   Eq.:  -0.244 ( -0.016)
       0.456 0.116 0.007 - 0.544 0.182 0.013 CL  -0.175 CF  -0.244
      [0.002 0.002 0.001 - 0.002 0.002 0.001 CL   0.006 CF   0.014]

    3. Rollout          bar/20 11/10                 Eq.:  -0.264 ( -0.037)
       0.443 0.108 0.006 - 0.557 0.160 0.007 CL  -0.184 CF  -0.264
      [0.002 0.002 0.001 - 0.002 0.002 0.001 CL   0.006 CF   0.015]

    4. Rollout          bar/24 13/8                  Eq.:  -0.305 ( -0.078)
       0.432 0.119 0.005 - 0.568 0.162 0.011 CL  -0.201 CF  -0.305
      [0.002 0.002 0.001 - 0.002 0.002 0.001 CL   0.005 CF   0.013]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 840326012 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]





[close]
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: diane on December 31, 2009, 10:49:09 PM
Erm, stupid question time....can I just ask, why is this move 1.5?  :wacko:
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: ah_clem on January 01, 2010, 09:58:13 PM
Quote from: diane on December 31, 2009, 10:49:09 PM
Erm, stupid question time....can I just ask, why is this move 1.5?  :wacko:

Gnubg started numbering the moves with 0, but I didn't notice right away and called the first move  "move 1". I'm calling this move "move 1.5" to get it back in synch with gnubg.

It's no more complicated than that, although I am tempted to throw in a move "e" and a move "pi". 
Title: Re: Game 1 Move 1.5 Forum to play 5-1
Post by: diane on January 02, 2010, 10:46:10 AM
:lol: :lol: