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21U

Posted By: Nack Ballard
Date: Sunday, 27 December 2009, at 1:09 a.m.

In Response To: 21U (rew)

Sticks rollout says this is 0.070 behind 21$ and 21S. Im a little bit skeptical, does anyone else have a big rollout of this opening move? One of the reasons Im skeptical is that 21U is able to come out on top after 51S-21.

For opening 21, I have the Snowie result shown below. (Click here to understand nacbracs.) To keep it simple, I will compare only S to U (their margins are underlined).

[$ S8 U48 D51 V64] 80k 5kUDV
Also, truncated: [$ S11 U59 D52 V75 W100] 1k

There is enough variance in a 5k rollout that (until it is extended) I typically average it with the trunc. So, I put Snowie's S vs U margin at -(.040 + .048) = -.044.

Gnu's 5k rollout is [$ S16 D67 U69] 46k 5kDU, with an S/U margin at .053. If we average the two bots' results, S beats U by (.044 + .053) / 2 = .048.

51S-21 produces a different correct move from that of opening 21 because the opponent can hit from the 23pt with 63 and 54. Instead of being .048 behind, U rolls out ahead of S by .020, .034 or .023, depending on the bot, an average of .026.

For 21S-21, U's .026 edge over S is erased and the two plays are tied because opp's hitting 63 is duplicated -- it could have been used constructively to make the 5pt.

For 41S-21, S pulls back into the lead: it is about .016 better than U because opp's hitting rolls from the 23pt, 63 and 54, are both duplicated.

Coming full circle, with opening 21, S increases its lead over U from .016 to .048 because Opp can't hit with 63 or 54 as she can (and happily would despite the point-making option) with 41S-21.

Hope that helps,

-Nack

Messages In This Thread

• 21U
  rew -- Saturday, 26 December 2009, at 6:43 p.m.
  • 21U
    Andreas -- Saturday, 26 December 2009, at 9:07 p.m.
    • 21U
      rew -- Saturday, 26 December 2009, at 9:33 p.m.
  • 21U
    David Rockwell -- Saturday, 26 December 2009, at 11:59 p.m.
    • 21U
      Nack Ballard -- Sunday, 27 December 2009, at 1:12 a.m.
      • 21U
        David Rockwell -- Sunday, 27 December 2009, at 2:24 a.m.
        • 51S21U better as 51S21 $
          Andreas -- Sunday, 27 December 2009, at 11:16 a.m.
          • 51S21U better as 51S21 $
            David Rockwell -- Sunday, 27 December 2009, at 2:57 p.m.
            • 51S21U better as 51S21 $
              Andreas -- Sunday, 27 December 2009, at 4:06 p.m.
              • 51S21U better as 51S21 $
                David Rockwell -- Sunday, 27 December 2009, at 4:39 p.m.
              • Ask First!
                Stick -- Sunday, 27 December 2009, at 4:53 p.m.
                • Hmm.. so close
                  neilkaz -- Sunday, 27 December 2009, at 5:07 p.m.
                  • Hmm.. so close
                    Nack Ballard -- Sunday, 27 December 2009, at 5:53 p.m.
                • Ask First!
                  Nack Ballard -- Sunday, 27 December 2009, at 5:25 p.m.
                  • ok: I will expand to V after getting the file, ty *NM*
                    Andreas -- Monday, 28 December 2009, at 9:06 a.m.
                • Ask First!
                  Timothy Chow -- Sunday, 27 December 2009, at 6:50 p.m.
                • Ask First! - OK I will
                  David Rockwell -- Monday, 28 December 2009, at 2:11 a.m.
                  • 51S-43 XG RO
                    Stick -- Monday, 28 December 2009, at 2:30 a.m.
                    • 51S-43 XG RO
                      Nack Ballard -- Monday, 28 December 2009, at 6:56 a.m.
          • Nactation question etc etc
            neilkaz -- Sunday, 27 December 2009, at 4:42 p.m.
            • Nactation question etc etc
              Stick -- Sunday, 27 December 2009, at 4:49 p.m.
              • What about for a 43 play?
                neilkaz -- Sunday, 27 December 2009, at 5:04 p.m.
                • What about for a 43 play?
                  Nack Ballard -- Sunday, 27 December 2009, at 5:42 p.m.
                • What about for a 43 play?
                  Timothy Chow -- Sunday, 27 December 2009, at 6:24 p.m.
                  • What about for a 43 play?
                    neilkaz -- Monday, 28 December 2009, at 4:47 p.m.
          • 51S21U better as 51S21 $
            Nack Ballard -- Sunday, 27 December 2009, at 4:43 p.m.
    • 21U
      Chuck Bower -- Sunday, 27 December 2009, at 3:05 p.m.
      • 21U
        David Rockwell -- Sunday, 27 December 2009, at 4:40 p.m.
  • 21U
    Nack Ballard -- Sunday, 27 December 2009, at 1:09 a.m.