FIBS Board backgammon forum

Backgammon => Fibsboard Forum Matches => FFM2 => Topic started by: Zorba on August 01, 2009, 07:04:49 PM

Poll
Question: 4-2 to play?
Option 1: 24/20 6/4 votes: 0
Option 2: 20/18 8/4 votes: 0
Option 3: 15/11 6/4 votes: 2
Option 4: 15/11 4/2* votes: 0
Option 5: 15/13 8/4 votes: 1
Option 6: 8/4 6/4 votes: 0
Option 7: 6/2* 4/2 votes: 10
Option 8: 24/20 4/2* votes: 1
Title: Game 3, move 11: Forum 4-2
Post by: Zorba on August 01, 2009, 07:04:49 PM
The Forum doubled and roadkillbooks accepted, now we (blue) have a 4-2 to play:

jDN4wEiznGCCIQ:QQmqACAAAAAA
Title: Re: Game 3, move 11: Forum 4-2
Post by: stog on August 01, 2009, 07:33:55 PM
Spoiler
where's my fave? 24/20, 4/2*..ah thank u!.........but now that i look again 6/2 4/2 is the only choice :))
[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: diane on August 02, 2009, 12:53:40 AM
Quote from: stog on August 01, 2009, 07:33:55 PM
Spoiler
6/2 4/2 is the only choice :))
[close]

I am very much in agreement with that  ;)  Here is hoping I am right  :laugh: :laugh:
Title: Re: Game 3, move 11: Forum 4-2
Post by: ah_clem on August 02, 2009, 02:03:45 AM
Spoiler
This is a very good roll for us.  Let's be thankful that we didn't let Diane roll the dice.  (c:

The main problem with this roll is that there are several good ways to play it.  We can simply make a fourth point and get our backman moving with 24/20 6/4. 

Or we can make a fourth point while safety-ing our lead blot with 8/4/ 6/4.

Both are good moves, but I think we need ot hit here because of the match score - let's go for gammon.

None of the loose hits do as much for us as the wne that hits and makes a fourth point.  So that's my choice -

6/2* 4/2.   Two men on the bar, a four point board, and the remaining open point leaves a very poor backgame for rkb if he manages to make a second point in our homeboard.




[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: diane on August 02, 2009, 08:39:23 AM
Quote from: ah_clem on August 02, 2009, 02:03:45 AM
Spoiler
Let's be thankful that we didn't let Diane roll the dice.  (c:
[close]

:blink: :blink:

The next game will be fun, when I am rolling the dice for everyone  ;)   :laugh: :laugh:
Title: Re: Game 3, move 11: Forum 4-2
Post by: ah_clem on August 03, 2009, 03:15:21 PM
Quote from: diane on August 02, 2009, 08:39:23 AM
:blink: :blink:

The next game will be fun, when I am rolling the dice for everyone  ;)   :laugh: :laugh:

Fun for our opponent, perhaps.  We are doomed. DOOMED I tell you....
Title: Re: Game 3, move 11: Forum 4-2
Post by: adrian on August 03, 2009, 06:44:12 PM
I wish a 44 for RKB  :laugh:  Our 62 42 calls for it !! :yes:
Title: Re: Game 3, move 11: Forum 4-2
Post by: ah_clem on August 03, 2009, 08:40:01 PM
Quote from: adrian on August 03, 2009, 06:44:12 PM
I wish a 44 for RKB  :laugh:  Our 62 42 calls for it !! :yes:

If he rolls that joker, I think we'll all know who to blame...
Title: Re: Game 3, move 11: Forum 4-2
Post by: diane on August 03, 2009, 08:45:43 PM
Quote from: ah_clem on August 03, 2009, 03:15:21 PM
Fun for our opponent, perhaps.  We are doomed. DOOMED I tell you....

You misunderstand, I will be rolling for our opponent too.... >:D >:D

It will be a case of 'may the least awful dice win'  :laugh: :laugh:
Title: Re: Game 3, move 11: Forum 4-2
Post by: diane on August 03, 2009, 08:48:18 PM
Quote from: adrian on August 03, 2009, 06:44:12 PM
I wish a 44 for RKB  :laugh:  Our 62 42 calls for it !! :yes:

:blink: :blink: Someone gag that man!!!

:lol:
Title: Re: Game 3, move 11: Forum 4-2
Post by: ah_clem on August 03, 2009, 11:36:42 PM
gnubg results.  Let me know if I screwed it up again (c:


Spoiler
   

Good (easy?) decision by the forum.

Evaluation

1. Cubeful 2-ply    6/2* 4/2                     Eq.:  +0.598
       0.634 0.324 0.007 - 0.366 0.078 0.002
    2. Cubeful 2-ply    15/13 8/4                    Eq.:  +0.538 ( -0.060)
       0.628 0.284 0.011 - 0.372 0.071 0.002
    3. Cubeful 2-ply    15/11 6/4                    Eq.:  +0.524 ( -0.073)
       0.621 0.289 0.011 - 0.379 0.078 0.002
    4. Cubeful 2-ply    8/4 6/4                      Eq.:  +0.484 ( -0.114)
       0.610 0.280 0.011 - 0.390 0.081 0.002
    5. Cubeful 2-ply    20/18 8/4                    Eq.:  +0.478 ( -0.119)
       0.607 0.283 0.011 - 0.393 0.096 0.004
        2-ply cubeful prune [world class]

Rollout

    1. Rollout          6/2* 4/2                     Eq.:  +0.445
       0.588 0.292 0.007 - 0.412 0.100 0.003 CL  +0.517 CF  +0.445
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.003 CF   0.003]
    2. Rollout          15/13 8/4                    Eq.:  +0.415 ( -0.030)
       0.589 0.267 0.009 - 0.411 0.093 0.002 CL  +0.492 CF  +0.415
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.003 CF   0.003]
    3. Rollout          15/11 6/4                    Eq.:  +0.404 ( -0.041)
       0.579 0.275 0.010 - 0.421 0.101 0.003 CL  +0.478 CF  +0.404
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.003 CF   0.003]
        Truncated cubeful rollout (depth 11) with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 861747477 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]


Rollout with MWC
    1. Rollout          6/2* 4/2                     MWC:  40.48%
       0.588 0.292 0.007 - 0.412 0.100 0.003 CL  41.72% CF  40.48%
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.05% CF   0.05%]
    2. Rollout          15/13 8/4                    MWC:  39.96% ( -0.52%)
       0.589 0.267 0.009 - 0.411 0.093 0.002 CL  41.28% CF  39.96%
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.05% CF   0.05%]       
    3. Rollout          15/11 6/4                    MWC:  39.77% ( -0.71%)
       0.579 0.275 0.010 - 0.421 0.101 0.003 CL  41.05% CF  39.77%
      [0.001 0.001 0.000 - 0.001 0.001 0.000 CL   0.05% CF   0.06%]
        Truncated cubeful rollout (depth 11) with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 861747477 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]



[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: lewscannon on August 04, 2009, 06:13:48 PM
Spoiler
This is interesting. My vote to make the 4 point stands alone. I am willing to gamble that rkb dances here and then go after his blot on the 2 point if he does. We still have to get a lot of pieces around the board and I don't want to see him with a double blockade on the 4 and the 5 as we're coming around.
[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: ah_clem on August 04, 2009, 07:37:08 PM
Spoiler

Quote from: lewscannon on August 04, 2009, 06:13:48 PM
My vote to make the 4 point stands alone. I am willing to gamble that rkb dances here and then go after his blot on the 2 point if he does. We still have to get a lot of pieces around the board and I don't want to see him with a double blockade on the 4 and the 5 as we're coming around.

My take is that I'd rather face a blockade on the 4 & 5 than a backgame against the 2 and 5.   Of course, I'm teh suck at backgames so what do I know?  But regardless of which is a stronger second point for rkb, putting a second checker on the roof makes it harder to make that second point.   And even with my sucky backgame skills, I know that one point ain't enough to mount a backgame.


[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: lewscannon on August 04, 2009, 08:03:37 PM
Quote from: ah_clem on August 04, 2009, 07:37:08 PM
Spoiler

My take is that I'd rather face a blockade on the 4 & 5 than a backgame against the 2 and 5.   Of course, I'm teh suck at backgames so what do I know?  But regardless of which is a stronger second point for rkb, putting a second checker on the roof makes it harder to make that second point.   And even with my sucky backgame skills, I know that one point ain't enough to mount a backgame.


[close]

Spoiler
It looks like gnu disagrees with me, along with the rest of the forum. Eh, what does it know? :-) You guys (and ladies) are probably right to hit the 2nd piece, though I now reserve the right to say 'I told you so' later on.
[close]
Title: Re: Game 3, move 11: Forum 4-2
Post by: Zorba on August 05, 2009, 03:21:35 PM
Your rollout looks good there, ah_clem. You might get slightly better results overall if you truncate at an even number of plies, 10 or 12. Better yet, don't use truncation at all, but that takes some extra time. Below are my results from a 2-ply rollout, the best play didn't change, but the equities and their differences changed a bit as a result of higher settings.

Spoiler

Pointing on the 2pt is clearly better than just making the 4pt, it wins more games and especially more gammons. At the score, it's not so close anymore.

   1. Rollout          6/2* 4/2                     Eq.:  +0,4940
       60,85  29,67   0,11 -  39,15   9,96   1,79 CL  +0,5687 CF  +0,4940
     [  0,20   0,24   0,06 -   0,20   0,29   0,28 CL   0,0058 CF   0,0065]
   2. Rollout          15/13 8/4                    Eq.:  +0,4385 ( -0,0555)
       59,75  26,60   0,59 -  40,25   9,04   1,38 CL  +0,5213 CF  +0,4385
     [  0,21   0,22   0,07 -   0,21   0,31   0,22 CL   0,0062 CF   0,0069]
   3. Rollout          15/11 6/4                    Eq.:  +0,4370 ( -0,0570)
       59,59  27,16   0,59 -  40,41   9,62   1,03 CL  +0,5187 CF  +0,4370
     [  0,21   0,22   0,08 -   0,21   0,28   0,23 CL   0,0061 CF   0,0068]

       Full cubeful rollout with var.redn.
       1296 games, Mersenne Twister dice gen. with seed 861201809 and quasi-random dice
       Play:  2-ply cubeful prune [world class]
       keep the first 0 0-ply moves and up to 8 more moves within equity 0,13
       Skip pruning for 1-ply moves.
       Cube: 2-ply cubeful prune [world class]

[close]