(1) Is it possible to calculate this re-cube action over-the-board in a reasonable amount of time?
I think you could calculate this over the board in a reasonable time if you knew (1) your match equity table, and (2) that if you take, this position ...
The score (after 0 games) is: White 0, Blue 3 (match to 9 points)
Move number 7: White on roll, cube decision?
| White | 5 | ||
|---|---|---|---|
                | |||
| Blue | 3 | ||
| Position ID: BwAA8AEAAAAAAA Match ID: AgEgAQAAGAAE | |||
... will occur 5/6 of the time and is a redouble to 8 with you winning about 25% of the time (the other 1/6 of the time you lose 4 points).
So in the original position,
| (1) | if you pass, you trail 9-away 4-away for 21% MWC | |
| (2) | if you take, there are only two outcomes to calculate | |
| (a) | you trail 9-away 2-away for 10% MWC about 16% of the time | |
| (and 10% of 16% is 1.6%) | ||
| (b) | you lead 1-away 6-away Crawford for about 89% MWC about 21% of the time (because 1/4 of 5/6 = 5/24 = 20.8%) | |
| (and 89% of 21% is 18.7%) |
Since 1.6% + 18.7% = 20.3%, less than 21%, White should pass in the original position.
(2) For Blue to properly calculate whether to re-double, must he determine his MWC if White takes AND re-cubes to 8 (if Blue does not roll an initial doublet), and compare that MWC to his MWC if White drops?
No, not here. Blue doesn't have to calculate his no-double equity, since he can first ask whether White should take, and since White should pass, the double is automatic, assuming equal players.