Problem of the Week #12: May 25




Cash game, center cube. Black on roll.

(a) Should Black double?

(b) If doubled, should White take, drop, or beaver?

Black leads the race, has made an advanced anchor, made his 5 points and has put white on the bar. Definitely double.

It's early but white has absolutely nothing going for him here, His best case scenario is to hopefully enter and get some kind of decent holding game. This can be hard enough, since black has nothing to fear with his anchor and whites undeveloped position Worst case scenario is getting blitzed off the board and losing a gammon. I think white should pass.

At first sight it seems an easy double take. I will take a look at it again tomorrow and reconsider, but what comes to my mind right now is that it's a double because you otherwise risk losing your market. The only thing that would make me hesitate is the fact that you only have 2 checkers on the 8 point + the stacked 6 point. Which also makes it a fairly easy take imo. These however are first thoughts, having taken a quick look at it... I'll prolly nuance after a second look or i might even change my mind completely (wouldn't be the first time).

Bit of a weird position. I'm trying to figure out the "point" of this problem. For some reason, even though my instinct says this is a double (because I'm not sure whether White should take or pass, meaning this should be approximately an optimal point to double) I have the feeling that the point of this problem is that it isn't a double.

Anyway, I can do no more than go along with my pitiful intuition about the cube. My gut says double, drop. White's position is just hopeless and he has few good rolls to extract himself from this mess. The only thing that gives me pause about the drop is I think it's less likely than it might appear that Black will gammon White.

Edit: By the way Robertie (assuming you're reading this) maybe you should put the solution in a reply in this thread, in "spoil" tags. That way we all get notified (through the subscribed threads page) when the solution is up.

I think it's a very good double (white has no offense and could be blitzed/gammoned) but white should take. In white's favor black still has two men back, an overstacked six point, and a stripped eight point. These weaknesses give white at least a 30% shot or so and relatively few gammons for black.

~ Rick

agreed, double and take. Black hasn't done too much yet, and not likely to strenghthen his inner board soon unless he rolls a double.

Second look.
I still think it's a clear double.
I'm not so sure about the take however. The more I look at it, the more reasons I see to drop. White is well behind in the pipcount (137 vs 173 if I my quick calculation is correct), black is on roll so blacks lead will increase even more. White has no board whatsoever, no builders, a stacked 13-point, one checker on the bar and one on the ace point. There is the possibility of getting blitzed (which will lead to a gammon a very high percentage of the time) and black has very few bad rolls. In the end, there are hardly any reasons to take this cube. A vast percentage of the time, you will just end up trying to fend off a gammon, I think. The board just looks nasty from white's point of view. It's like having a nightmare and when the cube is offered you get the choice whether you want the nightmare to become worse or to have it stop.

Edit: the pipcount is 149 vs 173, which does change the matter. Right now I'm doubting again...

Double-drop.

This position looks like it's about 5-6 rolls into the game, and what does white have to show for it? Nothing. In fact, it's negative. He's on the bar, he has no spare on his 8 point, and he's stacked at the midpoint which makes his position inflexible. Black has everything going for him. He has an advanced anchor, a second home board point made, and an extra builder in the outfield.

I think white's position is much much weaker than it may initially seem.

(I'm not even sure how white ended up like this in the first place. Did he slot the 3 point from the 8 point? It almost looks like a contrived position. Maybe the spare on the 8 was moved back to the midpoint or something to make the drop more clear... But enough meta-analysis...)

We might be overvaluating blacks position a bit here. Although white doesn't have much to work with, the game is far from over. I disagree when you say that black has everything going for him. He doesn't have a spare on his 8-point either and still has 2 checkers to swing around (although from his semi-advanced anker and not from the ace point).
I think this is a really tough position to judge. In the end, the only reason to double I can think of is the risk of losing you market. White's position may be weaker then it initially seems, but maybe the same goes for black.

How does white win?

1) Race: Unlikely. He's around 20 behind on the bar and it's not his roll. Running prospects don't look good.
2) Prime: Unlikely. Black has an advanced anchor and white hasn't developed anything.
3) Blitz: Not a chance. Black has an anchor and a building advantage.
4) Late hit off the anchor: Barring the fluke sequences, this is the way that white is going to have to pull out a victory. But for this to happen, white first needs an anchor. Black already owns the 5 point, which is the best point from which to play one of these games. White's most likely anchor to hold is the ace point since that's where his blot is, and this is (I think) the weakest point to play from. When he wins one of these games, he wins two (since he took the cube and isn't winning a gammon), but when he loses he sometimes loses four because he won't necessarily get the anchor, giving black a clear pathway to gammons. Black can (and probably should) be hitting pretty loose as long as white doesn't have an anchor. To make matters worse, white has some stacks which will make his rolls a bit awkward for a while, leaving blots for black to pick up, increasing those gammon chances.

Winning prospects are slim, and with lots of gammons going against him without winning very many himself, I don't see this being a take. (Of course, I got the last cube problem wrong... so what do I know? )

I think Aaron's explanation sounds really good. From black's perspective, black has basically no bad rolls, and things are pretty great after 64, 62, 42, 11-66, 63, 53...this list is getting pretty long. It looks like one of those positions where none of black's assets are overwhelming by themselves (decent anchor, decent board, decent race lead, attack prospects), but the combination of all of them means white is really going to have to fight to get back into this.

WARNING SERIOUS SPOILERS AHEAD MATIES