Problem of the Week #8: April 27



Part (a): Early in the game. Cash game, center cube. Black to play 6-4.



Part (b): Early in the game. Cash game, center cube. Black to play 6-4.


The positions are apparently similar, but the correct play of 6-4 is different in each position. Can you see why?

Part (a): I take The Bar with 13/7 11/7 Gives us a nice little Three Point block and we still have builders.

Part (b): I think I still go with 13/7 11/7, but could take 10/4 8/4 to preserve my ability to hit the lone White man as he tries to escape.

A) 10/4, 8/4. Black needs to establish a point in the inner board rather than make the bar because he will be looking to hit loose in white's outfield or inner board immediately if possible. Playing this way gains an instant advantage in any ensuing hitting game, where making the bar point does not.

B) 13/7, 11/7. By taking white's bar point last roll, this has become a holding game. The objective is now to conserve pips while establishing a blockade and wait for good doubles or a timely hit. Making black's bar point has become more important than the four point for two reasons. It begins the blockade with three consecutive points instead of gaps. It also uses one fewer crossover than making the four point, thus preserving pips.

The 2 reasonable choices are between making the 4 point or the 7 point in each example.

A)

White is stacked on the midpoint and their own 6 point and does not have an inner board point made yet. If we make the 7 point it gives us 3 points in a row with some builders available to make a possible 4 point prime next roll. So I feel 13-7, 11-7 is the best play.

B) White now has an inner board point made on the 22 and we have an advanced anchor available to help catch white if he runs. Matching white's board strength is more important than the connectivity of the points we make in this case, especially since we can now also hit a possible runner from 3 points instead of 2. I think these factors make 10-4, 8-4 the best play.

I can't see any other reasonable moves than taking the bar or four point.

In (a) I'd take the four point playing 10/4 8/4. With black's checkers back on the 24 point and white's candlesticks he should have plenty of chances to hit white as he comes off his awkward position. Here the four point hurts white more when he tries to re-enter after a hit.

In (b) I'd take the bar playing 13/7 11/7. Note that black's rear checkers are on white's bar point. Here black is trying to avoid exchanges of hits and bring these guys home while blocking the single checker white has back on his 24 point. Making the bar works better as a block (as compared to an exchange of hits) and creates a safe landing point for black as he brings his remaining checkers in from the outfield.

Good problem, great series on modern opening roles!

~ Rick

I like cashedout's reasoning very much, so I vote for his solution.