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XG odd/even effect

Posted By: Nack Ballard
Date: Thursday, 3 June 2010, at 11:00 p.m.

In Response To: XG odd/even effect (Matt Cohn-Geier)

I'm pretty sure that there is an odd/even effect in XG. Probably it has more weight for cube decisions than for checker play.

Here is some evidence of a significant odd/even effect in checker play (though there may be another explanation):

Opening 64
3m/4c [P R10] 107k
4-ply [R P4] 46k (swing of .014)

If you click on "3m/4c," you'll see a 3-ply move, 4-ply cube rollout. And if you click on "4-ply," you'll see a 4-ply move, 4-ply cube rollout. That is, the difference is isolated to checker movement (3-ply vs 4-ply).

While I'm on the subject, here is a list of positions (all first and second roll, nothing complicated) for which XG 3-ply and XG 4-ply rollouts produce a noteworthy difference in the margin between plays:

41$-44
3-ply [P D14] 67k
4-ply [D P9] 15k (swing of .023)

Opening 41
3-ply [S $8] 173k
4-ply [S $22] 25k (swing of .014)

Opening 43
3-ply [D U14] 46k
4-ply [D U27] 10k (swing of .013)

32D-22
3-ply [N E2 @12] 51k
4-ply [N E11 @24] 20k 10k@ (swings of .009 and .012)

64P-22
3-ply [E N10] 15k
4-ply [E N1] 46k (swing of .009)

62S-32
3-ply [U S3 W4 T26 Z27 H30] 46k 5kTZH
4-ply [U S14 W15 H38 T39 Z42] 15k 5kHTZ (swings of .011, .011, .013, .015 and .008)

21$-54
3-ply [S R15] 165k
4-ply [S R7] 19k (swing of .008)

That accounts for about 8 of the 29 first and second roll money positions rolled out on both XG 3-ply and 4-ply so far.

And here a couple at gammon save:

Opening 43 (gammon save)
3-ply s[U Z6 S11] 5k
4-ply s[Z S1 U9] 46k 10kU (swings of .015 and .020)

Opening 51 (gammon save)
3-ply s[$ S2] 5k
4-ply s[S $7] 27k (swing of .009)

Key: P = Point, R = Run, S = Split, Z = reverse split, $ = Slot, D = Down, U = Up, N = Near(-side quadrants), E = Each (home board), @ = anchor, W = Wild (split-and-slot), T = sTack/Tower, H = Hit.

Error sizes are in thousandths. After the brackets is the number of trials (in thousands, rounded down). For example, "[S R15] 165k" means that S is best and R is -.015 after 165,000+ trials.

Nack

Messages In This Thread

• 21 to play from the roof
  Adam Versaw -- Monday, 31 May 2010, at 1:53 p.m.
  • My quick thoughts OTB
    neilkaz -- Monday, 31 May 2010, at 2:58 p.m.
  • 21 to play from the roof
    Timothy Chow -- Monday, 31 May 2010, at 6:34 p.m.
  • some rollouts
    Klaus Evers -- Wednesday, 2 June 2010, at 8:55 p.m.
    • some rollouts
      Timothy Chow -- Wednesday, 2 June 2010, at 9:03 p.m.
  • Rollout 3 ply
    Adam Versaw -- Thursday, 3 June 2010, at 10:09 a.m.
    • compare Rockwell-Kaz to G11 and different plies in RO: odd/even effect in XG?
      Klaus Evers -- Thursday, 3 June 2010, at 1:10 p.m.
      • compare Rockwell-Kaz to G11 and different plies in RO: odd/even effect in XG?
        Timothy Chow -- Thursday, 3 June 2010, at 3:16 p.m.
        • compare Rockwell-Kaz to G11 and different plies in RO: odd/even effect in XG?
          Klaus Evers -- Thursday, 3 June 2010, at 3:56 p.m.
          • XG odd/even effect
            Matt Cohn-Geier -- Thursday, 3 June 2010, at 4:50 p.m.
            • XG odd/even effect
              Leonardo Jerkovic -- Thursday, 3 June 2010, at 6:26 p.m.
            • XG odd/even effect
              Nack Ballard -- Thursday, 3 June 2010, at 11:00 p.m.
              • XG odd/even effect
                misja -- Friday, 4 June 2010, at 3:15 p.m.
                • XG odd/even effect
                  Nack Ballard -- Friday, 4 June 2010, at 9:22 p.m.
      • rollout and g11
        Adam Versaw -- Thursday, 3 June 2010, at 11:33 p.m.