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problem at truncation -

Posted By: Daniel Murphy
Date: Tuesday, 31 July 2012, at 4:45 a.m.

In Response To: problem at truncation - (eXtreme Gammon)

Looking for an explanation of why both XG Roller++ and Gnubg have the wrong play on top after a truncated 7-ply rollout.

For what it's worth, here's one 7 roll sequence in which White rolls a single 5.

After 7 plays Gnubg 2-ply evaluation underestimates wins and gammons, when Blue started with 10/5*/2, and overestimates wins and gammons, when Blue started with 15/10 6/3.

Blue leads 8-0/11.

53 10/5*/2	53 bar/20
36 15/9 6/3	44 -
35 9/4 3/off	34 -
11 6/5*/4 6/5(2)

White	174
Blue	47
Position ID: zB5wQHC7OwcAAA Match ID: UYlkAQAAQAAE

	Wins	Gammons	Meaningless Backgammons	Cubeful EMG Equity
2-ply evaluation	97.88%	94.34%	16.25%	+1.385585
2-ply rollout	98.10%	95.87%	35.81%	+1.470954

---

53 15/10 6/3	53 bar/20
36 15/9 6/3	44 -
35 9/4 3/off	34 -
11 4/2 4/3 1/off

White	169
Blue	47
Position ID: zB5wwGC39wwAAA Match ID: UYlkAQAAQAAE

	Wins	Gammons	Meaningless Backgammons	Cubeful EMG Equity
2-ply evaluation	97.87%	95.57%	2.68%	+1.413175
2-ply rollout	96.58%	94.74%	15.86%	+1.431230

Messages In This Thread

• Stick's Matches from Novi
  Dmitriy Obukhov -- Monday, 30 July 2012, at 3:22 a.m.
  • Stick's Matches from Novi
    Stick -- Monday, 30 July 2012, at 4:07 a.m.
    • Stick's Matches from Novi
      David Wells -- Monday, 30 July 2012, at 8:19 a.m.
  • Stick vs Merriman: XG++ Data Makes No Sense
    Paul Weaver -- Monday, 30 July 2012, at 8:57 a.m.
    • Stick vs Merriman: XG++ Data Makes No Sense
      Carlo Melzi -- Monday, 30 July 2012, at 10:08 a.m.
      • Stick vs Merriman: XG++ Data Makes No Sense
        Bob Koca -- Monday, 30 July 2012, at 2:27 p.m.
    • Stick vs Merriman: XG++ Data Makes No Sense
      Rick Janowski -- Monday, 30 July 2012, at 3:09 p.m.
      • Stick vs Merriman: XG++ Data Makes No Sense
        Bob Koca -- Monday, 30 July 2012, at 4:04 p.m.
        • Stick vs Merriman: XG++ Data Makes No Sense
          Keene -- Monday, 30 July 2012, at 4:32 p.m.
          • Stick vs Merriman: XG++ Data Makes No Sense
            Bob koca -- Monday, 30 July 2012, at 4:53 p.m.
        • Stick vs Merriman: XG++ Data Makes No Sense
          Rick Janowski -- Monday, 30 July 2012, at 5:53 p.m.
    • RO and XG is having issues with this score and cube position it seems
      neilkaz -- Monday, 30 July 2012, at 3:42 p.m.
    • Stick vs Merriman: XG++ Data Makes No Sense
      Stick -- Monday, 30 July 2012, at 3:47 p.m.
      • Stick vs Merriman: XG++ Data Makes No Sense
        Rick Janowski -- Monday, 30 July 2012, at 5:48 p.m.
    • Stick vs Merriman: XG++ Data Makes No Sense
      Daniel Murphy -- Monday, 30 July 2012, at 6:27 p.m.
      • problem at truncation -
        eXtreme Gammon -- Monday, 30 July 2012, at 7:34 p.m.
        • problem at truncation -
          Daniel Murphy -- Tuesday, 31 July 2012, at 4:45 a.m.
      • GnuBg settings to mimic XGR++
        Taper_Mike -- Tuesday, 31 July 2012, at 12:36 a.m.
        • GnuBg settings to mimic XGR++
          Daniel Murphy -- Tuesday, 31 July 2012, at 1:55 a.m.
          • GnuBg settings to mimic XGR++
            Taper_Mike -- Tuesday, 31 July 2012, at 5:28 a.m.
            • GnuBg settings to mimic XGR++
              Daniel Murphy -- Tuesday, 31 July 2012, at 6:25 a.m.
              • GnuBg settings to mimic XGR++
                Taper_Mike -- Tuesday, 31 July 2012, at 10:58 a.m.