Fibsboard Forum Match 17 Game 1 Herd Cube Decision

[stog]

Happy Xmas..

Fibsboard Forum Match 17 Game 1 Herd Cube Decision

[ah_clem]

Spoiler

All "normal" prime vs prime are takes. There's nothing particularly unusual about this one, so I'll say it's a take.

Our opponent has a better anchor and better timing, and if he whacks the blot we are in some trouble.  But our blockade is strong - at least as strong as his - so I'll put our GWC somewhere north of 30%, far above the ~19% raw takepoint at 5a 5a.  And I'm just not seeing enough gammons to justify dropping.

Is this even a cube?  Not sure, but it's not my problem at the moment.

[close]

[ah_clem]

Since the decision is settled and we are unlikely to recube any time soon nothing is given away by posting a rollout:

Spoiler

This may be a good practical double if you think your opponent may pass, but this is an easy take.  Especially if you know the pipcount.

BTW, this will probably be the last rollout for about ten days since I'm travelling and won't have access to XG.  Maybe I'll get it together to post a gnu rollout or two.  Happy holidays all.

XGID=-BbB-BBBB---bA--bc-bbb--B-:0:0:1:00:0:0:0:5:10

X:Player 1   O:Player 2
Score is X:0 O:0 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X        O  O    |   | O  O  O        X |
|          O  O    |   | O  O  O        X |
|             O    |   |                  |
|                  |   |                  |
|                  |   |                  |
|                  |BAR|                  |
|                  |   |                  |
|                  |   |                  |
|                  |   |                  |
| O           X  X |   | X  X     X  O  X |
| O           X  X |   | X  X     X  O  X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 121  O: 144 X-O: 0-0/5
Cube: 1
X on roll, cube action

Analyzed in Rollout
No double
 Player Winning Chances:   36.78% (G:11.30% B:0.51%)
 Opponent Winning Chances: 63.22% (G:19.20% B:1.00%)
Double/Take
 Player Winning Chances:   36.79% (G:11.80% B:1.02%)
 Opponent Winning Chances: 63.21% (G:18.68% B:1.41%)

Cubeless Equities: No Double=-0.343, Double=-0.686

Cubeful Equities:
      No double:     -0.539
      Double/Take:   -1.207 (-0.668)
      Double/Pass:   +1.000 (+1.539)

Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 23.2%

Rollout:
 1296 Games rolled with Variance Reduction.
 Moves: 3-ply, cube decisions: XG Roller
 Confidence No Double: ± 0.015 (-0.553..-0.524)
 Confidence Double:    ± 0.019 (-1.226..-1.188)

 Double Decision confidence: 100.0%
 Take Decision confidence: 100.0%

 Duration: 8 minutes 35 seconds

eXtreme Gammon Version: 2.10, MET: Kazaross XG2

[close]

[Zorba]

ah_clem, you rolled it out  with The Herd cubing instead of el_micho.

I'll try a GNUbg 2-ply "world class" rollout, see what comes out.

[Zorba]

Spoiler

Even though it's a very easy take, it's a good cube that el_micho found here.

It all seems a matter of various timing advantages here, combined with the volatily of either el_micho rolling a great number or us rolling a very bad number, so enough market losers. The advantage of his 2pt anchor over our 1pt anchor, the 23 pips deficit for him giving more leeway before cracking the blockade, and very important and easy to miss: our two checkers out of play on the acepoint, severely hampering our possibilities to play ugly rolls.

Cube analysis
Rollout cubeless equity  +0.4225 (Money:  +0.4203)

Cubeful equities:
1. Double, take         +0.6994
2. Double, pass         +1.0000  ( +0.3006)
3. No double            +0.5680  ( -0.1314)
Proper cube action: Double, take

Rollout details:
Centered 1-cube:
  0.6513 0.2155 0.0110 - 0.3487 0.1043 0.0044 CL  +0.4225 CF  +0.5680
[0.0014 0.0019 0.0009 - 0.0014 0.0015 0.0004 CL   0.0047 CF   0.0091]
Player The Herd owns 2-cube:
  0.6630 0.2181 0.0134 - 0.3370 0.1083 0.0117 CL  +0.9620 CF  +0.6994
[0.0018 0.0030 0.0008 - 0.0018 0.0017 0.0017 CL   0.0121 CF   0.0141]
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 730862448 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]

[close]