Problem of the Week #9: May 5




Cash game, center cube. Black to play 4-3.


This position is from a match played some years ago in Monte Carlo. The opponents were two former World Champions: Paul Magriel (Black) and Philip Marmorstein of Germany (White). (It was early in a long match and the score had no bearing on the play, so I’ve turned it into a cash game problem.)

The players are involved in what’s called a mutual holding game, where both sides have an advanced anchor. Black leads by 17 pips in the race, 124 to 141. With the 4-3, Magriel decided it was a good time to break his anchor by 18/11, relying on the duplication of sixes and White’s awkward home board. Was he correct? If not, what’s a better plan and why?

Breaking the anchor is OK but why not 18/15 18/14? Now threes are duplicated and if not hit with a two the checkers should be reasonably easy to clean up (or no more difficult than before) or can be used to make outfield points that block white's men on the five point. Note that white is not so far behind that he's not worth blocking and pointing on if he leaves with one man.

~ Rick

I would prefer the 18/15 18/14 move...although I am nothing more than a backgammon past-time player

As tempting as it may be to run while white has the five point slotted with no builders, black should still be looking for a safer play. There really isn't duplication of sixes with 18/11 because white has no intention of breaking the anchor in black's home board with a variety return shots available. I would not leave white's bar point so soon as white may be able to afford hitting loose from the stacked midpoint with rolls like 6-2, 6-3, and 3-3.

The only move which doesn't leave white any immediate shots is 7/4, 7/3. Vacating the bar has the disadvantage of removing a key landing spot when bringing the back checkers around, as well as negating the threat of a six point prime if white breaks anchor. This is too much to give up for the safety of leaving no shot here.

Moving off the midpoint with 13/10, 13/9 is interesting as it may induce white to break anchor. The problem here is that once black brings those two blots home, loss of control over the outfield gives up too much to white who is far better timed to succeed in the holding game.

This leaves the somewhat awkward looking play of 13/6 to consider. The idea here is to leave only an immediate 3-1 for white to hit and cover. If white can not do something about the five point next roll, then there is also the possibility of remaking the midpoint with rolls like 5-2, 5-3, 5-4, 4-1, and 3-2.

I'm going to play 13/6 because it appears to have the fewest problems among the set of unattractive moves for this bad roll.

I think doing anything but clearing the rear anchor is delaying and making it more difficult to clear it next roll. Only doubles really help, and even if those are rolled it gives white time to improve his home board. I thought 13/6 had merit, but it doesn't leave many good future rolls. 7/3 7/4 is similar. 18/11 is more contstructive, and reduces the likelihood of leaving future blots if white misses.

18/14 18/15 leaves a double direct shot and fewer return shots. I don't understand its appeal.

I think it has to be 13/6 here.

18/11 gives white an opportunity to hit loose to get back into the game with the smallest consequences. If he hits loose on the bar point (he's not going to break the anchor to hit loose), and if you dance his position looks very threatening (your blot on the 11 point makes this even worse). Compare this to 13/6, where if he hits loose and you dance, you've still got the bar point to help you escape in the next couple rolls.

18/14 18/15 is a disaster waiting to happen. All you do with that play is give white the chance to go on the offensive. Leaving a double direct shot in front of a point with plenty of spares can't be a good idea.

18/11 looks good to me. White is in bad shape to attack and especially hitting with aces isn't that appealing for him. Waiting usually means whites position will be stronger and ours weaker, when we are forced to leave. Some of the scenarios where we get hit might also lead to more gammon wins for us if we hit back.

18/11 looks good to me. The reason is that it's about the time to run off the anchor and no other play looks good. White's board is weak for the moment, but it will improve in the next couple of rolls, and white will have plenty of rolls to keep his anchor and 12pt/17pt, so we will leave blots later when white has a much stronger board.

Interesting play for 18/14 18/15, cos 18/11 also leaves double shots. 21,31 hit and cover 5p while 51 hits too. I choose 18/11 because it's safer -- white may pick up the two blots once at a time if we do 18/14 18/15.