Problem of the Week #134: January 15


(a) Money game, Black owns a 2-cube.




Black to play 6-4.


(b) Money game, Black owns a 2-cube.




Black to play 6-4.


Note: All ‘cash game’ problems assume the Jacoby Rule is in effect. That is, you can’t win a gammon unless the cube has been turned.

I'm a total noob so I look forward to being wrong and being corrected.

a)8/2 8/4
b)7/1 5/1

Neither position looks great.

I preferred 20/10 in a as I don't feel I need the anchor given white's position and being on 10 will help me close up the board if I get a hit.

In b, I would go with 7/1 5/1 to try to close up the home board immediately as I feel the anchor is more important due to white's extra point.

In both Parts (a) and (b), White will try to avoid leaving a shot unless it is forced. Meanwhile, Black will be holding his anchor, and building the strongest board he can. In Part (a), White has two spares to play, so it is unlikely that he will be leaving a shot immediately. In Part (b) however, White is stripped, and so he will have to clear one of his outside points on his next turn when he rolls any 4, 5 or 6. In the attempt, he will often be forced to expose a blot.

In Part (a), Black can afford to slot the 4pt and 1pt. Even with two tantalizing blots in Black’s inner board, White will not want to leave a fly shot if he can avoid it. Black’s broken six-point prime is strong enough to deter that. Slotting the 4pt and the 2pt is weaker; it leaves only one number to cover the 4pt, while the alternative leaves two.

In Part (b), Black should make the 1pt, leaving no blots in his home board. With a possible fly shot upcoming, he does not want to be caught with two blots there.

My Solutions:

Part (a): 8/4, 7/1
Part (b): 7/1, 5/1

For the Record
I am so often wrong that I like to post my record in these messages. It's kind of a truth-in-advertising thing. Grunch: I have been answering these problems without the use of a bot, and before checking the excellent solutions of others, since Problem 28. My record at this writing is 52%.

Running when so far behind in the race is usually a bad idea.

Breaking the anchor gives White fresh pick-and-pass options when he rolls 31 and 34. And although 33 is a likely winner for White anyway, giving him extra POH (point-on-head) opportunities will only make things worse.

Ah yes, I completely forgot about the option of slotting. I guess I didn't learn from 2 weeks ago!!

Thanks

In both cases, race is 117-82 in favor of White. Despite White's wasted pips in his board, he has a solid lead, even with Black on roll. Somehow, Black must maintain as much contact as possible. Let's see...

(a) If White can safety one of his back men, he would probably do it next turn and leave an indirect shot while Black's board isn't too dangerous yet, because it will surely improve. Otherwise, he will play safe from his 8-pt. Therefore, since Black will have at most an indirect shot next turn, he can afford to slot with 8/4 8/2, preparing to make either or both these points next turn.

(b) Here, White has now 3 stripped points in the outfield and could leave a direct shot next turn (4-2). Otherwise, some rolls leave an indirect shot (4-1, 5-1, 6-1). In this case, I think Black should make an inner point now with 7/1 5/1, even if it's not the point he would have liked to make. Anyway, if Black hits White, he will probably fall in blitz mode rather than prime mode.

(a) 8/4 8/2
(b) 7/1 5/1

In fact, it would leave 2 numbers to cover (3s and 1s) instead of 3 numbers (4s, 3s and 1s), so that's a little less dramatic, but your play might still be the winner!

Grunch

In both situations, I go 5/1, 7/1. Make points in the home board. Wait for a shot.

a) 8/4 8/2, double slot, preparing the reception committee. white has spares so we have a to wait a little bit for our shot.

b) 7/1 5/1 All those stripped points, our shot is coming sooner.

Now that I see this reasoning, I agree with the 8/4, 7/1. Slotting the 4 this way does indeed let us cover with 3 numbers which would give us our 5 prime. More ways to make our 4 point > having our 4 and 2 slotted to make our points in order but with less ways to make them.

a - 20/14 8/4
b - 8/4 and either 8/2 or 7/1

8/4 7/1 does appear to be the better slot based on covering numbers, and also if we get binked on the 1, he's still potentially behind a 5-prime next turn and not on the edge. If we get hit on the 2, that's just bad in every way. When the shots are potentially coming this turn, making the point should be right over double-slotting.

a) 8/4 7/1
b) 7/1 5/1

Grunch: a) 20-14-10; b) 7-1,5-1.