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Position for your thoughts Herd...

Started by diane, July 17, 2010, 10:51:28 AM

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diane

White is on roll, should he recube, and should blue take?



Rocki and I discussed this position, I feel it is not quite a double, given the lead is only +4.  Rocki is happy for me to post this to discuss whether or not he was robbed blind  ;)
Never give up on the things that make you smile

stog

Spoiler
opening game of 5, so double/gambling take: might be different at other scores..ie double/drop
[close]

dorbel

Spoiler
This is quite a nice reference position; one to remember if you can. For money (or at the start of a long match) this is a marginal take/pass. The redouble is optimal and White wins 2 points of Blue passes and averages 2 points per game profit if he takes. Any improvement in Blue's position makes it a correct take, any deterioration makes it a clear pass. Some points to note.
Blue doesn't have a closed board. Adjusting the position so that Blue does have a closed board with the same pipcount, gives him a reasonable take, as White will then be reluctant to hit loose.
Blue's blot is a mirage, as any time he hits a shot (excepting hits that include a 6), he can pick up, so you don't need to worry about it too much.
Blue's pipcount is misleadingly good, as the extra checkers on the two and one points will probably lead to extra wastage in the bearoff.
White MUST redouble, even with only a four pip lead, as he has attacking chances against the straggler and any hit/dance sequence is an enormous market leader. White will point if he can of course and pick and pass, but should he hit with numbers like 4-3?  Yes, playing 6/1, 6/2 is not an option, burying checkers on the low points (bad, see above) and increasing your chances of leaving an involuntary shot next turn.

So finally, is the cube decision the same at this score? No, at 5-away, 5-away, this is a big pass. Redoubles that threaten to get you to the Crawford game are very strong. Of course the taker might get to Crawford as well, but he does that less than one time in 4 here. You actually need to win about 28% cubeless to take at this score! Owning the cube isn't worth much to him, as he can rarely offer an effective recube to 8.
Those of who don't have a match equity table, get one! Then compare what happens if you take and what happens if you pass to try and get a handle on what is happening here.

Nice position, very instructive and as I say, well worth remembering. Thanks stog.
All the facts and figures are courtesy of Snowie, so can't really be seriously argued against.
[close]

diane

Spoiler
Interesting, dorbel says double / pass, gnu analysis says double / pass, but double / take is leading 5-0.  This suggests most players would wrongly take, as I did.
[close]
Never give up on the things that make you smile

ah_clem

I haven't read the other replies yet, but it looks like a pretty clear double.  White is within a pip or two of it being a "racing double" (i.e. a double if it were a straight race).  But it's not a race and White has 12 rolls that are pretty devastating (any double, or the pick-and-pass numbers). That additional 33% to win this roll should push it over the edge.

Is White ahead? yup.  Are there market losers?  You bet!  Ship the cube.

Blue has some chances, so I think it's a take.

blitzxz

Yet another misunderstanding to me in this one. I was so hard trying to see what is the score and match length (I even had to adjust my resolution to do so) that I didn't notice that the cube was already on 2.