[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

BGonline.org Forums

Which part is easier ? - Rollout of the fake position

Posted By: pierrez
Date: Thursday, 16 April 2026, at 12:15 p.m.

In Response To: Which part is easier ? (pierrez)

Ok guys. Someone unveiled the trap.

The idea was twofold :

Part 1 : to illustrate on a psychological side, how players at all levels are focussed on either strategical or tactical moves or both, but are globally blind. It is true that, usually, tactical moves don’t involve the total of checkers in play, but only a partial amount locally, when strategical moves highlight interaction of the checkers distribution on the whole board.

I guess it happened quite a few to the readers to start and complete a game in a tournament (not in a chouette) with only 14 checkers. I have never heard of a game played with 16 checkers but if someone knows a story.

Part 2 : Back to the fake position. If we assume that this position is in between these two,


 
 
 
 





White is Joueur 2

score: 0
pip: 126
Unlimited Game
Jacoby Beaver
pip: 126
score: 0

Blue is Joueur 1
XGID=---ACaC-B--AdDA--baca-ba--:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

Analyzed in Rollout No double Double/Take
Player Winning Chances: 63,53% (G:14,90% B:0,41%) 63,74% (G:15,58% B:0,46%)
Opponent Winning Chances: 36,47% (G:7,80% B:0,29%) 36,26% (G:8,06% B:0,25%)
Cubeless Equities +0,343 +0,704
Cubeful Equities
No double:+0,499±0,010 (+0,488..+0,509)
Double/Take:+0,464 (-0,035)±0,016 (+0,448..+0,480)
Double/Pass:+1,000 (+0,501)
Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 6,4%
Rollout details
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:100,0%
Take Decision confidence:100,0%
Duration: 36 minutes 55 seconds

eXtreme Gammon Version: 2.19.211.pre-release





White is Joueur 2

score: 0
pip: 126
Unlimited Game
Jacoby Beaver
pip: 121
score: 0

Blue is Joueur 1
XGID=---ACaC-C--AdCA--baca-ba--:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

Analyzed in Rollout No double Double/Take
Player Winning Chances: 68,63% (G:11,99% B:0,21%) 68,35% (G:15,60% B:0,32%)
Opponent Winning Chances: 31,37% (G:4,45% B:0,12%) 31,65% (G:5,79% B:0,18%)
Cubeless Equities +0,449 +0,933
Cubeful Equities
No double:+0,659 (-0,050)±0,008 (+0,651..+0,667)
Double/Take:+0,709±0,012 (+0,697..+0,721)
Double/Pass:+1,000 (+0,291)
Best Cube action: Double / Take
Rollout details
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:100,0%
Take Decision confidence:100,0%
Duration: 26 minutes 09 seconds

eXtreme Gammon Version: 2.10

Obviously, the additional spare on the 8pt put Blue in Double territory, but does the 4th spare (in the fake position) on the 13pt add some value to the Blue equity ?

No doubt, if Blue can start a blitz, but unclear in the case of an exchange of hits are turning bad for Blue.

As to the take, it seems still a take, maybe less confortable.

Messages In This Thread

 

Post Response

Your Name:
Your E-Mail Address:
Subject:
Message:

If necessary, enter your password below:

Password:

 

 

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

BGonline.org Forums is maintained by Stick with WebBBS 5.12.