BGonline.org Forums

'Too Good' in Match Play?

Posted By: Albert Steg
Date: Tuesday, 19 January 2016, at 9:49 p.m.

Still getting the hang of understanding XG equities in various situations, and this one has me a little puzzled. In this position we have white holding a 2-cube in a gammonish position and XG indicating 'No Double'. Clearly it would be silly to double here, allowing black an immediate recipe to 8, especially with all those perfectly efficient gammons for the match.

		White is ASteg score: 2 pip: 111 13 point match pip: 151 score: 9 Blue is VAshkenazi
XGID=--CEDbab-a---------cbb-bAB:1:-1:-1:00:2:9:0:13:10
Blue on roll, cube action?

Analyzed in 4-ply	No redouble	Redouble/Take
Player Winning Chances:	88.48% (G:35.51% B:2.41%)	88.62% (G:33.64% B:1.98%)
Opponent Winning Chances:	11.52% (G:2.47% B:0.06%)	11.38% (G:2.28% B:0.05%)
Cubeless Equities	+1.025	+1.265
Cubeful Equities
No redouble:	+0.970
Redouble/Take:	+0.813 (-0.157)
Redouble/Pass:	+1.000 (+0.030)
Best Cube action: No redouble / Take
Percentage of wrong pass needed to make the double decision right: 45.7%

eXtreme Gammon Version: 2.10, MET: Kazaross XG2

Okay, that looks fine. But then, a few rolls later, we get this:

		White is ASteg score: 2 pip: 110 13 point match pip: 129 score: 9 Blue is VAshkenazi
XGID=--CEDb-b-------a---cbbabBA:1:-1:-1:00:2:9:0:13:10
Blue on roll, cube action?

Analyzed in 4-ply	No redouble	Redouble/Take
Player Winning Chances:	90.20% (G:31.50% B:1.79%)	90.29% (G:30.32% B:1.69%)
Opponent Winning Chances:	9.80% (G:1.88% B:0.04%)	9.71% (G:1.68% B:0.04%)
Cubeless Equities	+1.034	+1.354
Cubeful Equities
No redouble:	+1.012
Redouble/Take:	+0.973 (-0.039)
Redouble/Pass:	+1.000 (-0.012)
Best Cube action: No redouble / Take

eXtreme Gammon Version: 2.10, MET: Kazaross XG2

. . . and . . . nevermind? What I was going to ask about was that when I view this position within XG, for 'Best Choice' it reads "Too Good to redouble / Take" -- which was a head-scratcher since it was in a sense 'Too Good' all along -- but having copied to BGonline format I see that as displayed here it has the expected "No Redouble / Take."

So, I guess this is just a little glitch of some kind, not very significant, but I'll post this anyhow in case its a little bug worth swatting.

Messages In This Thread

• 'Too Good' in Match Play?
  Albert Steg -- Tuesday, 19 January 2016, at 9:49 p.m.
  • 'Too Good' in Match Play?
    Timothy Chow -- Wednesday, 20 January 2016, at 3:00 a.m.
    • 'Too Good' in Match Play?
      Albert Steg -- Wednesday, 20 January 2016, at 4:57 p.m.