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Bots and basic holding games....(again and long)

Posted By: neilkaz
Date: Sunday, 20 September 2009, at 3:39 p.m.

While going over the Depreli positions it became clear to me that a decent portion of the equity tossed by GNU and Snowie on cube decisions was due to overvaluing positions where the trailer has a single anchor game as the major source of his take equity. Both GNU (2 ply) and Snowie almost always and sometimes significantly overvalue the defender's chances in holding games and as a result both cube them later than is optimal and take cubes that they should clearly pass.

XG seems to suffer less from this disease from what I've seen. We'll let Frank post BGB evals here if he wants. Here's a basic 5 pt holding game that is a pass since the race lead is too much and there's decent timing. Posession of the bar pt means that a 65 will clear the mid pt later and that once the mid is cleared, future shot equity is small. Here's the GNU rollout. LOL ..no this position isn't TG, it is just that GNU in the rollout takes clear passes next turn.

The score (after 0 games) is: gnubg 0, user 0

Move number 8: user on roll, cube decision?

gnubg	146
user	123
Position ID: sG2LAQOYu4MHAA Match ID: cAkAAAAAAAAA

• user doubles

Alert: wrong double ( -0.0062)!

Cube decision
Rollout cubeless equity		+0.5885
Cubeful equities:
1.	No double	+1.0062
2.	Double, take	+1.0999	+0.0937
3.	Double, pass	+1.0000	-0.0062
Proper cube action:		Too good to double, pass (6.2%)
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.7882 0.0201 0.0007 - 0.2118 0.0085 0.0002 +0.5885 +1.0062 Standard error 0.0009 0.0007 0.0004 - 0.0009 0.0004 0.0001 0.0020 0.0047 Player gnubg owns 2-cube 0.7978 0.0205 0.0006 - 0.2022 0.0089 0.0005 +1.2147 +1.0999 Standard error 0.0009 0.0009 0.0004 - 0.0009 0.0006 0.0002 0.0043 0.0052
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 865987911 and quasi-random dice
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

Now for GNU 2 ply eval..which underestimates the leader's chances just as Snowie does. Snowie says 76.7% total wins and a .925 take on 3 ply.

The score (after 0 games) is: gnubg 0, user 0

Move number 8: user on roll, cube decision?

gnubg	146
user	123
Position ID: sG2LAQOYu4MHAA Match ID: cAkAAAAAAAAA

• user doubles

Cube decision
2-ply cubeless equity		+0.5451
	0.7667 0.0215 0.0002 - 0.2333 0.0101 0.0001
Cubeful equities:
1.	Double, take	+0.9316
2.	Double, pass	+1.0000	+0.0684
3.	No double	+0.8848	-0.0467
Proper cube action:		Double, take

Now for GNU 3 ply, which lucks into the proper decision since 3 ply evals usually have the side on roll..ie the leader in cube decisions winning a couple percent more games.

The score (after 0 games) is: gnubg 0, user 0

Move number 8: user on roll, cube decision?

gnubg	146
user	123
Position ID: sG2LAQOYu4MHAA Match ID: cAkAAAAAAAAA

• user doubles

Cube decision
3-ply cubeless equity		+0.5931
	0.7880 0.0276 0.0004 - 0.2120 0.0108 0.0000
Cubeful equities:
1.	Double, pass	+1.0000
2.	Double, take	+1.0420	+0.0420
3.	No double	+0.9538	-0.0462
Proper cube action:		Double, pass

OK here's a long XG rollout to compare and we see that it is close to the GNU rollout.

is Player 2 score: 0 pip: 146

Money session

pip: 123 score: 0 is Player 1

XGID=----BbCCC---bD-abbbbb-----:0:0:1:D:0:0:3:0:10

double to 2 take ?

Analyzed in Rollout
Player Winning Chances:	79.43% (G: 2.53% B: 0.08%)
Opponent Winning Chances:	20.57% (G: 0.75% B: 0.02%)
Cubeless Equities
No Double:	+0.589
Double:	+1.214
Cubeful Equities
No Double:	+0.986 (-0.014)
Double/Take:	+1.117 (+0.117)
Double/Drop:	+1.000
Best Cube action: Double / Drop
Rollout details
5184 Games rolled with Variance Reduction. Moves and cube decisions: 3 ply
Confidence No Double:	± 0.005 (+0.981...+0.991)
Confidence Double:	± 0.007 (+1.110...+1.125)
Double Decision confidence:	100.0%
Take Decision confidence:	100.0%
Duration: 5 hours 19 minutes 41 seconds

Version: 1.03

Now for the XG 3 ply (equiv GNU 2 ply) evaluation. There's small fluctuation between XG's plies but XG is passing this cube on all plies.

is Player 2 score: 0 pip: 146

Money session

pip: 123 score: 0 is Player 1

XGID=----BbCCC---bD-abbbbb-----:0:0:1:D:0:0:3:0:10

double to 2 take ?

Analyzed in 3 ply
Player Winning Chances:	78.56% (G: 2.42% B: 0.06%)
Opponent Winning Chances:	21.44% (G: 0.81% B: 0.02%)
Cubeless Equities
No Double:	+0.571
Double:	+1.176
Cubeful Equities
No Double:	+0.945 (-0.055)
Double/Take:	+1.025 (+0.025)
Double/Drop:	+1.000
Best Cube action: Double / Drop

Version: 1.03

is Player 2 score: 0 pip: 146

Money session

pip: 123 score: 0 is Player 1

XGID=----BbCCC---bD-abbbbb-----:0:0:1:D:0:0:3:0:10

double to 2 take ?

Analyzed in 4 ply
Player Winning Chances:	79.38% (G: 2.62% B: 0.04%)
Opponent Winning Chances:	20.62% (G: 0.90% B: 0.02%)
Cubeless Equities
No Double:	+0.588
Double:	+1.210
Cubeful Equities
No Double:	+0.963 (-0.037)
Double/Take:	+1.059 (+0.059)
Double/Drop:	+1.000
Best Cube action: Double / Drop

Version: 1.03

I sure do hope that if and when (lets hope it is when) GNU gets additional training, that the result will have improved evaluation of basic holding games.

I posted this long disertation here since I am often asked this online and now can refer people to here.

Messages In This Thread

• Bots and basic holding games....(again and long)
  neilkaz -- Sunday, 20 September 2009, at 3:39 p.m.
  • Bots and basic holding games....(again and long)
    Bob Koca -- Sunday, 20 September 2009, at 6:37 p.m.
    • Bots and basic holding games....(again and long)
      Rich Munitz -- Sunday, 20 September 2009, at 8:30 p.m.
      • Bots and basic holding games....(again and long)
        Bob Koca -- Sunday, 20 September 2009, at 9:27 p.m.
    • Bots and basic holding games....(again and long)
      Fabrice Liardet -- Monday, 21 September 2009, at 8:55 a.m.
    • Bots and basic holding games....(again and long)
      Ian Shaw -- Monday, 21 September 2009, at 1:51 p.m.
  • Bots and basic holding games....BGB
    Neil Robins -- Sunday, 20 September 2009, at 7:29 p.m.