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Roll Vs Roll: Match Play

Date: Wednesday, 8 October 2014, at 7:21 a.m.

In Response To: Roll Vs Roll: Match Play (AP)

Do you mean a generalised rule of thumb for n-roll versus m-roll at a-away,b-away with cube level c (i.e. all five parameters) ? That is a tall order, and I don't know of any such heuristic. As far as the example position goes, it is so volatile that any doublet roll now will lose your market if you get another roll (because it will be gin), and any non-doublet will make you only 16.67% gwc next roll if you get another roll. So it's a safe bet that you only really need to know the bottom end of the recube window, and whether you have more gwc than that now. Your cubeless gwc is you rolling a doublet in two rolls without him rolling a doublet, so that's (1-(5/6)*(5/6))*5/6 = 25.46%, so if that is more than the (Re)Doubling Point, you should recube. Doing a standard Risk/Reward calculation from a MET, you get Risk=(9a2a-0%)=9.80%; Reward=(1a6aCr-5a6a)=(88.73-56.63%)=32.10%. Risk/(Risk+Reward)=9.8/(9.8+32.1)=23.39%. Your 25.46% gwc puts you just inside the window, so you should recube. You simply don't have the luxury of trying to get an efficient recube.

For mental arithmetic purposes, if you round the MET figures to integers, and round the gwc calculation appropriately, you should get about 25% for the gwc, and 10/42 for the Doubling Point, which you can see is slightly less than 25%, therefore a recube. You won't be out by much if you're careful. These are the types of decision you save your clock time for, because I do know of any shortcuts.

I think you have to just do the math as best you can with these on a case by case basis, but if the position has more rolls left than this example, the maths would be too complex for most people OTB.

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