the dorbel daily

Thursday, 12 January 2012

Last Man Standing.

In the Christmas Quiz I emphasised the difficulty facing the player whose opponent has taken off 14 men. There are unusual checker plays that you have to make, but today I just want to look at using the cube.

Here's a position that you might face. Black hit White's's last man and closed her out and White has danced every time up to here. It's a money game, so what's the correct cube action for both sides?

Black didn't double and rolled 6-5, taking two off and White danced again leaving the position below.

Now what's the correct cube action for both sides?

I'll expand on this tomorrow, so if you want a comment, get it in now!

Enjoy the game!


Anonymous said...

Black is off in most 3 rolls,
White IF she gets in next roll will also be off in ± 3 rolls.

However Black on roll and will have at least 2 more off so that leaves black off in 2 and unlikely white will make it off in 2.

Time for black to pass the cube but I am unclear if it a take for white?

If she rolls a joker 6-6 or 5-5 she can still win.

ah_clem said...

The rule of thumb as I understand it is to double when you are 5 checkers behind the leader. Applying that here:

position 1 has White with 14 off and Black with 7 off - black is 7 checkers behind, so no double (and take of course.)

position 2 is 14 to 9, a difference of 5, so the rule would indicate it's a double (and also a take, since it's just at the double point.)

I'm sure that this simple rule can be refined, and look forward to hearing more about it tomorrow.

Steve said...

I think both positions are probably takes, position 2 obviously less comfortably so than 1. The question is, are they doubles in the first place? Black has plenty of potentially awkward rolls (anything with a 1) that leave him odd-ended or gapped. White could dances again, then gets a hit... Or she doesn't dance and Black still has some work to do, so I'm inclined to say both are no double/takes

Julia said...

The 5-behind rule says no double in (i), double in (ii). But I'm not sure how far that rule goes - usually we apply it when breaking a closed board and White has a middling number left. White needs 25 pips - 3 average rolls - and won't waste. In (i) Black is worse than a 4-roll position; any 1,2,3 wastes a whole roll (unless he ventures a double-shot, which can't be right!). In (ii) Black is much closer to a true 3-roll position - he has fewer wasting rolls and most of his doubles will save a roll, while White is worse than a true 3-roll position in that small doubles don't save a roll.

No double/take in (i), double/pass in (ii).