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back-nack convergence -- partial spoiler

Posted By: Nack Ballard
Date: Sunday, 4 July 2010, at 9:51 p.m.

In Response To: back-nack convergence -- partial spoiler (Stein Kulseth)

I had a similar experience. I found 5 rolls (2.5 moves) to be easy (there are a large number of solutions), and 4 rolls to be just out of reach.

To make it a little tougher on myself, I added a restriction that no doublets are rolled in this duplicate game. This works:

43E-61X-65K-32U-51U (backgammon)
43@-61Q-65R-32R-51D (Nackgammon)

[Translation to traditional notation: 43: 24/20 6/3, 61: 24/18 6/5*, 65: Bar/20* 13/7*, 32: Bar/23 Bar/22*, 51: Bar/20 24/23 (backgammon). And 43: 24/20 23/20, 61: 24/18 23/22, 65: 24/13, 32: 18/13, 51: 13/7 (Nackgammon).]

43-61-65-32-51 (with either BG or NG)

Variants are possible. For example, the third roll can be 51; or the fifth can be 42; or the first and fifth can be 54 and 32 (respectively). Or some of the rolls on the Nackgammon board can be played differently.

Even discounting variants, by no means do I claim that my non-doublets solution theme to be unique. (It's just that I didn't look for another.)

I'm not quite convinced that 4 rolls (2 moves) is impossible, but if a solution does exist I believe the final position must have a checker on the bar.

Nack

Messages In This Thread

• back-nack convergence
  Stein Kulseth -- Friday, 2 July 2010, at 2:43 p.m.
  • back-nack convergence
    Tom keith -- Saturday, 3 July 2010, at 2:51 a.m.
  • back-nack convergence -- partial spoiler
    Nack Ballard -- Saturday, 3 July 2010, at 8:38 a.m.
    • back-nack convergence -- partial spoiler
      Stein Kulseth -- Sunday, 4 July 2010, at 4:16 p.m.
      • back-nack convergence -- partial spoiler
        Casper van der Tak -- Sunday, 4 July 2010, at 4:38 p.m.
        • back-nack convergence -- partial spoiler
          Nack Ballard -- Sunday, 4 July 2010, at 9:55 p.m.
      • back-nack convergence -- partial spoiler
        Nack Ballard -- Sunday, 4 July 2010, at 9:51 p.m.