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

BGonline.org Forums

Can anyone explain this?

Posted By: Carlo Melzi
Date: Friday, 26 November 2010, at 10:36 a.m.

In Response To: Can anyone explain this? (John O'Hagan)

I was kind of asking myself a question similar to yours some time ago, when I encountered the position below leading -3-4 as white and holding a 2 cube.

Since I missed the recube and wanted to understand the position better, for comparison I created the second position, with white leading -2-4 and centered cube.

At the beginning I couldn’t realize the difference in the two positions. My first thoughts were the following:

  • if white does not double and wins a single game, score will be -C-4 in both cases
  • if white does not double and wins a gammon, white wins the match
  • if white doubles, black's takepoint is exactly the same (18,62%)
  • if white doubles and black takes, the match is on the line in both cases

Of course, what changes is the start of the doubling window for white, which is much higher in the second position.

This depends, as many have already said, on white's MWC if he holds the cube and loses: in the first case, white has only 40% MWC, in the second, white has 60% MWC.

Therefore, you should be less willing to ship the cube at -2-4 than to reship at -3-4.





is Player 2

score: 1
pip: 142
5 point match
pip: 146
score: 2

is Player 1
XGID=-c-aBBBB----AE---b-bb-babA:1:1:1:00:2:1:0:5:10
on roll, cube action?


Analyzed in XG Roller+
Player Winning Chances: 78,63% (G: 32,94% B: 2,93%)
Opponent Winning Chances: 21,37% (G: 8,85% B: 0,12%)
Cubeless Equities
No Redouble:+0,698
Redouble:+0,860
Cubeful Equities
No Redouble:+0,812 (-0,048)
Redouble/Take:+0,860
Redouble/Drop:+1,000 (+0,140)
Best Cube action: Redouble / Take

eXtreme Gammon Version: 1.20, MET: Rockwell-Kazaross
is Player 2

score: 1
pip: 142
5 point match
pip: 146
score: 3

is Player 1
XGID=-c-aBBBB----AE---b-bb-babA:0:0:1:00:3:1:0:5:10
on roll, cube action?


Analyzed in XG Roller+
Player Winning Chances: 78,45% (G: 33,08% B: 2,98%)
Opponent Winning Chances: 21,55% (G: 9,14% B: 0,15%)
Cubeless Equities
No Double:+1,056
Double:+1,317
Cubeful Equities
No Double:+0,814
Double/Take:+0,731 (-0,083)
Double/Drop:+1,000 (+0,186)
Best Cube action: No Double / Take

eXtreme Gammon Version: 1.20, MET: Rockwell-Kazaross

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.