What to Do When Nothing is Happening

What to Do When Nothing is Happening
by Walter Trice – 29 August 2006

As we saw in our previous article, it is quite possible for a game to be decided by a play that might easily be dismissed as insignificant. When you are waiting and hoping for a lucky break in a game that you are probably going to lose, it can be difficult to muster up the energy necessary for maximizing your chances.

Often the problems involve subtle details of checker-distribution and flexibility. But these details, in the extreme cases, can make for very large differences in equity. Consider Problem 1:

Is it too great a stretch to imagine that an opponent might make a “safe” play here? After all, Red might get another shot. And an opponent of mine actually did play 8/3 in this position. But 8/3 gives up a full 4.5% in winning chances, according to the Snowie rollout. It’s a huge, huge blunder, although my opponent in the actual game probably had no idea that he was even faced with an important decision.

Red should play 8/4, 2/1. In the long run he needs a strong home board for any winning game plan except the pure race. In the racing variations, too, his chances will be better without awkward stacks and gaps in his board. So he should just send his checkers where they need to go to help make the open points – even if it means that he will have to pass up an indirect hit that may come his way on the next roll! After 8/3 it would be much harder for Red to get the ace and four points made efficiently. Any spares on the 3 and 2 points would both have to go to the ace, and checkers to fill in the 4 would be available only on the two outfield points.

In Problem 2 above, the lazy man’s play would be a mistake. The 3 point can be made by moving only two checkers, but it is better to leave a blot in the outfield and play 13/3, 8/3, 6/1. The blot hinders White from clearing the midpoint with various aces, as well as rolls like 4-3 and 3-2, since White would really rather not leave two blots exposed to indirect shots. Red doesn’t even mind getting hit with 5-1 all that much. Getting hit will help him keep his timing for the deuce-point game. He is not too likely to be gammoned with White’s board starting out so weak.

In Problem 3 above, Red must obviously come out with the 5, 23/18, since the risk of getting attacked is too great if he remains in White’s home board. White might be leaving a shot with 6-1, but the parlay of 6-1/hit/White-rolls-a-3 is too unlikely to justify a play like 8/4 for the 4 part of the roll. Red should play his four 7/3, to be able to follow up by making the next home board point in the proper order. Red simply must build a strong board in order to win this game.

In Problem 4 above, now Red is quite likely to get a shot right away. Furthermore both numbers of his 2-1 roll can be played constructively for making the 3 point without slotting, as both 7/5 and 10/9 add builders that bear directly on the target point with new numbers.

Cube ownership actually makes the decision to play 7/5, 10/9 easier. With the cube on White’s side of the board Red would have to finish the game by closing out a hit checker, so at some point he would need to make the 3 point. But with cube access he will sometimes be able to cash the game before making the 3, so that the slot would amount to overkill – and an unnecessary risk.

The lazy play, moving only one checker (13/5), seems perfectly natural in Problem 5 above. But Red is not getting a shot here immediately because of White’s spare on the midpoint, so he should take the trouble to look for a play that does more. Red can make the 5 and start the 3 with 8/5, 8/3, but this would mean giving up a potentially useful priming point. The most aggressive play, and probably the best, is 8/3, 6/3, trying for a four point board and a five point prime before the shot comes.

But above in Problem 5A, when we take away White’s outfield spare, the possible immediate shot looms. Now the simple and solid 13/5 is best.

Problem 6 above is one that I have found to be intriguing and a bit baffling. I can’t pretend to even know surely which play is best. White does have a couple of shot-leaving rolls – 6-5 and 6-3 – and if he is going to roll one of them then Red will be better off if he has played 13/8. Otherwise he will rather have slotted the 3 point. For me the ‘natural’ slotting play would have been 8/3.

It took me a while to figure out why the Snowie recommendation of 6/3, 13/11 could possibly be better. The relatively few additional rolls to cover the three-point slot did not seem sufficient to justify leaving all those blots. There is a positional reason apart from the extra cover numbers: if you leave builders on the 8 and 7 points then the one that doesn’t cover the 3 is still available to make an outfield priming point. On the other hand after 8/3, if you cover 7/3 then the builder on the 6 point cannot move backwards.

I seriously doubt that 6/3, 13/11 is the best play by as great a margin as the Snowie rollout indicates. Perhaps it is merely the best play to make Snowie play the White side too aggressively! GNU seems to like 6/3, 13/11 by a much smaller margin. Jellyfish likes 13/8.

 

Here are the rollouts for the positions above:

Problem 1

Problem 2

Problem 3

Problem 4

Problem 5

Problem 5A

Problem 6