Problem of the Week #28: September 13


Cash game. Center cube. Black on move.




Part (a): Black to play 2-1.




Part (b): Black to play 6-5.

I tend to be a lurker to this forum as I am still in the infancy of learning the actual strategies of the game (and some of the insight shown in these threads is eye opening).

With that said, I am going to offer what I would likely do in this spot without exactly knowing how to properly explain it...

Position A

bar-23 and 6-5


Position B

21-10

I look forward to the actual experts dissecting it.

a) i dont know the exact strategy behind here, but im thinking that making the 22 or 23 point isnt our main priority just yet at this time in the match. i think we should be looking to make a better home board... and with white already having an anchor in there on the 3 point, i think the best play would be to attack our 4 point...

bar/24, 6/4*

b) i immediately thought of running with a piece on the 21 point, but white can easily hit that next throw. 8/2*, 6/1* seems a little too adventurous and risky and also leaves us with little to no checkers to cover up our 1 and 2 points afterwards... so im now thinking that 13/2* is the best move.

13/2*

a) bar 24/6/4*
making the 4 pt seems pretty crucial to eventually winning the game, so hitting on the 4 pt seems like a priority. white has tons of return shots (22 i think), but bearing in without the 4 pt will be a lot more difficult than w/ it. also the combo of black being far ahead in the race and white not having a great attacking set up makes anchoring on the 22 pt seem a nonpriority.

b) 21/16 21/15

black's way ahead in the race but he still has 3 checkers behind the 4 pt prime, so it seems like his priority should be to escape those checkers. hitting loose on the 2 point doesn't make much sense as the 2 pt isn't valuable given white's 3 pt anchor and potential to anchor on the 4pt from the bar. so i think just running with 21/16 21/15 is best. it leaves 2 blots versus the 1 blot of 21/10 but it doesn't allow white to point on black's head. the double shot is also less risky given white loses his midpoint i suppose.

a) Hitting seems absolutely mandatory, both for attack (hoping to make the 4-point) and defense (hoping to stop White from improving his position). So bar/24 6/4*.

b) The two choices seem to be 21/16 21/15 vs. 13/2*. I havent the faintest idea which is better.

a) bar/23, 22/21
Black is far ahead in the race and an anchor should be useful. So, I think it is best to take the best available point which would be 21 point.
b) 13/2*
Breaking the anchor on 21 looks a bit risky (but no a huge risk). However, it seems unnecessary. Black would like to move the spare from 23/21. Black shouldn't be too worried about the checker on the 2 point getting hit because he will still be ahead in the race. Also, if black gets hit and makes another point in white's board, he can really cause some headaches for white.

i really don't see anything redeeming about 13/2*

- Doesn't leave two blots
- Puts villain in the air when his position is inflexible
- Might lead to a home board point, always useful if a slugfest develops
- Keeps the defensive anchor

Not saying it's best, but it shouldn't be dismissed out of hand IMO.

leaves one less blot, but still leaves 16 shots at a much more important blot as black loses a lot more pips. plus this blot could have been used as a builder for the much more important 4 pt.

- white already has 5blots in black's very weak home board, so i can't see putting white on the bar as that disruptive
-ya, but the 2 pt is fairly irrelevant at this point given whites 3pt anchor and the poss to anchor on the 4pt.

- i suppose, but black is well ahead in the race, so he'll have to disengage first anyways. now seems like a good time since white's attacking stacks, the 18 and 17, are stripped so white will be leaving plenty of return shots

When is it correct to hit loose when you are almost certain to be hit back?
That's the theme connecting these two problems.

Part (a)
Black is in the middle of blot hitting contest, and this is certainly no time to stop. He may not be getting the best of it, but things gets much worse if he doesn't restrict white's options by putting him on the bar.

As a tempo play, the hit makes it harder for white to cover his bar point. After the hit, white has 10 numbers that enter and cover. If black does not hit, white has 17 covers.

But the hit is more than a pure tempo play. Black is slotting a key inner-board point, and if not hit, may cover soon. Of course, it is likely (but not certain) that he will be hit first.

Bar/24, 6/4*

Part (b)
The hit here is a pure tempo play. Black has rolled an awkward number, and must not play passively. His best move is to slot his bar in an attempt to equalize his prime, and then hit loose on the one point as a tempo. Once again, black's chances aren't great, but they get much worse with any other play.

13/7, 6/1*

a)bar-24 6-4 seems pretty good to me. Hitting seems more important , to avoid white priming . white has a bad spreading and structure. playing this way the only roll we are afraid is 4-6.

b)we have to settle timing here. i like for sure 21-15. even if we will be hit the white board is bad , with no center chekers. 13-8 or 21-16 to complete the move. I really don't see any advantage in hitting here , because we are giving white the opportunity to recover the bad timing he has.

calling 13/7 6/1* a 'tempo' play seems like a huge stretch. white does not have any imposing threats. 6/1* is basically just rendering a checker useless. then 13/7 is a pointless move as well because black is rarely going to actually be able to complete the bar point. only 8 rolls (11,22,55,66,65,12) do not let white return hit on the bar point after entering. and even then black still isn't a lock to roll a 1 or 6 next turn. plus 8 of white's entering rolls double hit on the 1pt and bar pt.

so basically it seems like 13/7 6/1* is a worse version of 13/2*. it has 0 positive benefits to it and plenty of negative ones.

Agree with position 1 being pretty clear, hitting on the 4....

Position 2...wow. 21/15 and then I really dont know. Maybe 21-16? 13-8?15-10?. I think running with both is probably ok as even if white hits, his other guys are too far to assist in the prime/close out etc.

*G*

a. bar/23, 22/21
b. 21/10

Battling for the Bar Points, Part (b)

In effect, three are only three points from which Black can play a six. Let’s consider all three in turn.

In counting return shots, we have ignored the possibility that White might hit on the two point in those cases where Black keeps his anchor on the four point.

Black Plays Six from His 21 Point
These plays all attempt to leverage Black’s lead in the race by running now. Even when Black is hit, he may easily reenter, and White may lose outfield control in the process when White hits from his midpoint.

The downside is that Black gives up a great advanced anchor. With each of these plays is Black is hit more often than not. He can be blitzed when White rolls one of his joker doubles. We might be able to live with that, but what about Black’s weak forward position? Can he really hope to tip-toe home with three backmen through a field of five white checkers? We might try this with a single checker, but not with three. So, with these plays, Black must expect to get hit, and must resign himself to recirculating some of his checkers before this game ends. If that’s the game plan, we’re keeping the anchor.

Play A
Black’s move: 21/10
White Fans: 0/36
White hits once: 18/36 - 33, 11, 53, 65, 64, 63, 62, 61, 51, 43
White hits twice: 4/36 - 66, 44, 33, 22

Play B
Black’s move: 21/15, 21/16
White Fans: 0/36
White hits once: 22/36 - 33, 22, 65, 64, 63, 54, 53, 42, 41, 32, 31, 21
White hits twice: 4/36 - 66, 44, 43

Play C
Black’s move: 21/15, 13/8
White Fans: 0/36
White hits once: 14/36 - 44, 11, 65, 53, 43, 32, 31, 21
White hits twice: 5/36 - 66, 33, 22, 63

Play D
Black’s move: 21/15, 6/1*
White Fans: 4/36 - 66, 55, 65
White hits once: 18/36 - any 1 (except 11), 44, 43, 33, 32, 22
White hits twice: 2/36 - 33, 11


Black Plays Six from His 13 Point
These plays save Black’s anchor. In a complex game where Black expects to be hit and recirculate his checkers, holding the anchor will be important.

Play E is the safest of all the plays considered here. It’s weakness is that it throws away a checker that belongs on the bar point or four point. Still, it might be the best of a bad lot.

Play F is the boldest of all. It has the highest risk, and the highest reward. By slotting the bar point, Black gives himself a 20% plus chance of making it on the next roll. Fully 11 shots miss Black completely, and when he is missed, he can cover two-thirds of the time. Even if Black is hit on the one point with 21 or 11, he has a few chances to enter and cover the bar point.

A subtle advantage to this play is that Black places his checker from the midpoint on a point he want to make, the bar point, rather than throwing it away. The checker he throws away comes from his over-stacked six point. When Black is hit, he’s back to the game plan that evolves from all these plays: recirculate his checkers, and try again later.

Play E
Black’s move: 13/2*
White Fans: 4/36 - 66, 55, 65
White hits once: 16/36 - any 2, 11, 41, 31
White hits twice: 0/36

Play F
Black’s move: 13/7, 6/1*
White Fans: 4/36 - 66, 55, 65
White hits once: 17/36 - 44, 33, 11, 54, 53, 52, 43, 42, 32, 21
White hits twice: 8/36 - 61, 51, 41, 31


Black Plays Six from His 8 Point
This has to be a loser. Black throws away two checkers with no appreciable gain.

Play G
Black’s move: 8/2*, 6/1*
White Fans: 4/36 - 66, 55, 65
White hits once: 17/36 - 22, 62, 61, 52, 51, 42, 41, 32, 31
White hits twice: 3/36 - 11, 21

Conclusion
All these plays are bad; Black would rather not move at all! Play F attempts to improve Black's offense. Play E tries to minimize the damage. I would choose between the two, with a slight preference for Play F.

a) bar/24 6/4*
b) 21/15 21/16