FIBS Board backgammon forum

15-13, 24-23 - can't see anything else to do with this, but will eagerly await better suggestions - these are the kinds of grotty rolls I always struggle to deal with correctly

I was also uncomfortable with tidying up and losing flexibility. I was thinking 15/14 13/11 but I hadn't taken the time to notice the duplication of threes. That makes 13/10 a better move.

15/13, you ran one backchecker to safety, that's still pretty good. Development should come later, with a roll that actually develops. Leaving and creating blots is not development: most likely you'll be safetying blot(s) next turn if they didn't get hit already, and you'd still have no development, but one extra blot on the tenpoint... Or you find yourself on the bar, not a good place for development either.

Duplication of threes is a minor point, since we also have ones to cover, and after hitting with a three, we'd have fives to cover as well. So leaving the blot actually gives the team 3-1, 3-3 and 3-5 (five rolls) to hit AND cover. The split backcheckers also give the team a lot of hitting rolls on the blot on 10: 6-3, 5-4, (3-3), 6-2, (5-3), that's six extra hitting rolls

24/23 is not an improvement, but not bad either, the checker should still be pretty safe on that point. 6/5 is not an option for factotum because of our split backcheckers.

*** EDIT: Oops! I just noticed I got the pipcount reversed, it's actually factotum 5 behind before the roll instead of ahead. Hmm.

That changes things. With the 3 pips rolled now, factotum will still be 2 behind with us on roll, for an effective 6 pips deficit.

Running a backchecker when behind in the race is not so good, especially not when it's combined with no development.

So, I now agree a more creative play is warranted. The race deficit makes blocking or attacking the opponent a more important factor. I'll go with factotum's 13/10 as the best way to do it.

This one is very clear:

    1. Rollout          13/10                        Eq.:  -0,2529
        46,47  10,71   0,67 -  53,53  18,52   1,31 CL  -0,1808 CF  -0,2529
      [  0,19   0,16   0,10 -   0,19   0,25   0,17 CL   0,0063 CF   0,0166]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 819163693 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]
    2. Rollout          24/23 13/11                  Eq.:  -0,3183 ( -0,0653)
        45,13  10,04   0,62 -  54,87  19,67   1,44 CL  -0,2330 CF  -0,3183
      [  0,18   0,14   0,09 -   0,18   0,22   0,20 CL   0,0057 CF   0,0144]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 819163693 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]
    3. Rollout          15/14 13/11                  Eq.:  -0,3301 ( -0,0771)
        45,12  10,30   0,58 -  54,88  19,37   1,38 CL  -0,2310 CF  -0,3301
      [  0,17   0,12   0,09 -   0,17   0,24   0,17 CL   0,0056 CF   0,0137]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 819163693 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]
    4. Rollout          13/11 6/5                    Eq.:  -0,3516 ( -0,0987)
        44,80  10,54   0,72 -  55,20  20,81   2,39 CL  -0,2295 CF  -0,3516
      [  0,20   0,16   0,13 -   0,20   0,26   0,25 CL   0,0075 CF   0,0180]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 819163693 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]
    5. Rollout          24/23 15/13                  Eq.:  -0,3929 ( -0,1399)
        44,60   8,88   0,53 -  55,40  19,98   1,24 CL  -0,2688 CF  -0,3929
      [  0,17   0,15   0,09 -   0,17   0,24   0,19 CL   0,0055 CF   0,0149]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 819163693 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]


Modified position: two checkers from the midpoint to the eightpoint, hardly development, but would give factotum a 5 pip lead instead of deficit, see attachment. GNUBG 4-ply:

    1. Cubeful 4-ply    24/23 15/13                  Eq.:  -0,1222
        49,49  11,06   0,41 -  50,51  16,19   0,31
        4-ply cubeful prune
    2. Cubeful 4-ply    13/10                        Eq.:  -0,1683 ( -0,0461)
        48,02  12,49   0,47 -  51,98  17,62   0,60
        4-ply cubeful prune