Problem of the Week #34: October 25


Cash game. White owns the cube. Black on move.




Black to play 3-3.

You have White on the ropes, and finding a hit somewhere to attempt a closeout is virtually mandatory.

It's not like you have any other goal in this type of position.

6/3* is an obvious possibility, but it removes a builder and there isn't much of a follow-up anywhere.

So 13/4* to start with, and then you might as well keep going with 4/1*.

13/4*/1*

Rather than launch a nebulous attack, Black should simply make the two outfield points.

The problem with the blitz is that Black does not have the checkers in place to follow it up. White is almost certain to make an anchor before Black can close him out. With 13/4*, 6/3*, Black leaves six blots scattered around the board, and only one builder to cover the two in his home board. 13/4*/1* is somewhat better, but still leaves five blots, and only one direct cover for his ace point.

The alternative of making the bar point is not as strong as making the eight and ten points. As Jeremy Bagai is fond of saying, two good things are better than one. In addition, making the bar would leave two outer board blots for White to shoot at.

Because White's front position is so weak, Black can forego making an advanced anchor on this turn. Instead, he should lock up (for the moment) the lead he now has, and await further developments.

My solution: 14/8, 13/10(2).

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. 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 50% correct.
Correct: 28(a), 29, 30, 32
Incorrect: 28(b), 31, 33(a), 33(b)

Ummm... no.

And so what if he does? Then you can worry about things like outfield points, with a position that is still very strong.

With the 5-point made and White having made no progress, you are virtually freerolling on the closeout attempt.

You can also flip this around and look at it from White's perspective. Would you rather have 2 on the bar against a 3-point board, when you are fighting for your life, or a chance to roll and move freely to try to improve your position, when almost every roll is good for you?

And I just want to add that the reason I know all this is that the bots attack me in this spot EVERY SINGLE ****ING TIME, and I dance three times in a row EVERY SINGLE ****ING TIME, and they close me out EVERY SINGLE ****ING TIME, so if I am wrong, it's because I'm cursed.

Tough problem. I think we can quickly dispense with any move that makes White's bar point. That just allows White to dump blots in his board on awkward rolls. The choice would appear to be between all-out attack with 13/4*/1* and the more prosaic 14/8, 13/10(2).

I tend to think that Black doesn't have the ammo for a closeout and should therefore sit on his lead and wait with the quieter option. But I think the two are going to be close.

Completely agree with pineapple.

13/1**
I think you want to be aggressive here and try to shut black out.
The last thing you want to do is let him make an anchor and get back in the game.

White has no board at all, so it isn't urgent to anchor now. It doesn't seem an attacking roll: the double hit in our board is way too risky and we cannot cover the mess after. Just hitting on the 4-point (13/4) leaves 15 shots in our board (not counting other blots), so I would not play that (true, having a stronger board, that favors us in a hit contest, but we lead by 17 before the roll, so why play bold if we don't need to?).

Then, we can make the bar point with 13/7 (2). But it would leave 4 blots and 27 shots, not counting White's shots in his board. But since he has good chances to anchor on the 4-point, the bar point maybe isn't that useful.

Why not use that roll to clear some blots and build some key blocking points? With 14/8 13/10 (2), Black clears all his blots outside White's home board and build 2 blocking points, especially the 10-point if White is to anchor on the 4-point. If somehow he fails to anchor there, Black then has builders for the 4-point. The downside is that the midpoint, 10-point and 8-point are all stripped, but since White has not even the beginning of a board, we'll be able to move our stragglers before breaking those points.

14/8 13/10 (2)

I'm ashamed that I haven't even thought about 13/4*/1*. Tempting, since the cube is already shipped and gammons count. It puts pressure on White right away. But what if the attack fails and White hits and anchors? No big deal because White has no board at all, but that would equalize the race and give White hope.

Let's say White rolls 1-1 or 4-4, he's back big time. It boils down to: do we win gammons twice as often as we lose games with the bold play? I'm not convinced. But I agree with pineapple888 about the bots. They would probably close me out with lightning speed!

I stay with the safe play.

I go for kill here with the double hit 13/1. There's a huge draw towards putting two up on the bar when you have your opponent outboarded by a lot. There's almost no downside to it! Even if white anchors or enters with a double, I don't think your winning chances are decreased all that much relative to some safe play, but the aggressive play here surely drives up your gammon chances a large amount.

What can I say, except I’m schizophrenic! I like my move, but I agree with everything Pineapple888, Aaron W, Mute and Ferregi have to say. Of course, I also agree with ChrisV and Uberkuber!

For fun (that’s what I call it), I played 13/4*/1*, and rolled this out a handful of times. Not too see who wins, but just too see if White anchors as often as I thought. As soon as he did, or else was closed out, I began again. Usually, it only takes a few rolls per trial. Here are some observations:

• White anchors readily, so easily, in fact, that I stopped after only five tests. I figured Black must get most of his close outs in the games where White dances on his first roll.
• When White does anchor, it is often on the three or four point, with three or four of Black’s checkers out of play behind him. Black is left with a busted blitz. Although Black is favored, the game is up for grabs.

Next, I rolled out thirty trials based on the assumption that White fans on his first try from the bar. Black gets the first roll thereafter. Same rules: I just wanted to learn whether White can make an anchor. I played ultra aggressively, pushing for a close out far longer than would be wise in a real game. These conclusions assume White has fanned:

• Even under these conditions, Black completed the close out only nine times, and failed twenty-one times. After dancing, White can make an anchor about two times in three. Combined with the results above, I estimate that White’s overall chance of anchoring are between 85% and 90%.
• When White does anchor, the scenario described by Pineapple888 comes to pass in most cases. That is, White is a huge dog in more than three of every four trials.
• White’s third checker plays a big part in the outcome. Even assuming entry failure on his first roll, White often has thirteen shots to cover the three point on his second roll.
• The third checker also helps White when he anchors on the one point. White can use his third man to start the three or four point, and, in many cases, successfully roll the anchor forward.
• Black has an interesting choice when he rolls a five. Should he cover on the ace point, or hit White’s third blot on the three point? My preference in a real game would be to cover, but in keeping with the idea of preventing White from anchoring at all costs, I played 56 and 54 to hit on the three point, using the other number to bring down a builder to within direct range of the cover. With 53, I hit, making the three point. Of course, 55 is brutal for White. With other fives, I covered the ace point.
• The only Black blots that tend to get hit are those in his home board. Black’s many other blots face only minimal risk. White often voluntarily passes up an opportunity to hit outside.

In the single trial where I played 14/8, 13/10(2), White rolled badly (54), and Black immediately re-launched his attack. The close out was nearly automatic.

As ChrisV suggests, is probably a close call. Granting White compete freedom of movement grates against my instincts. Pineapple888 is probably right; White must be silently begging not to be hit. Still, if Black pauses here to gather his forces, frequently he will find himself back on the attack on his next turn. If not, he is left with a fine, winning position.

My solution (still): 14/8, 13/10(2).

I don't know why people think there's a likely closeout here. You don't really have the ammunition for it. You've got a blot on the 8 point and a spare on the 6 point, but nobody else is in range to keep up the attack. It probably happens more often if you hit two than when you don't hit two, but that's not how you should expect to win from this spot.

Hitting simply keeps white from making any forward progress. On his side of the board, the only "progress" is that he has another spare on his 8 point. If you give him a free roll he can start to build up some long-term assets (11 makes a 4-prime, 31 makes his 5-point, 42 points on your head, 22 points on your head, 33 makes two home board points, 61 makes the bar point, 55 makes two home board points and puts you on the bar).

pretty standard DOUBLE HIT ( 13-1 ) imo .

its gotta be 13/1** here.

Making two outside points is soo passive here. Not going for the extra gammons seems criminal in a spot where i cant imagine we sacrifice too many wins (if any).

also im not too worried about leaving our blots since (1) white has a terribly weak home board and (2) white is gonna have to scramble to be able to hit them (besides the one point) in the first place. 1-1, 3-3, and 4-4 are gonna be big for white no matter what we do with this turn so im not gonna let those rolls deter me.

finally, yes white may anchor before we close out, but white will anchor if we dont hit even more easily, so Im not sure why this is relevant.

Also I should note that I was probably too glib in my first post. When I said "attempt a closeout" that doesn't mean go crazy and just hit at any opportunity on future rolls. I probably should have just said "attacking is clear" and left it at that. Others have expanded on the virtues of that approach.

Hero can re-evaluate the attack at any point, but putting two on the bar in this spot is very strong in any case.

I don't think this idea is correct. The only bad roll I can find for White is 5-4. Everything else either anchors (or makes the 9-point with 6-5) or hits and covers on the other side of the board (or does something else useful if you decide not to do one of those things).

No one has suggested 13/4* 6/3* ? It double hits, doesn't bury a checker on the 1pt, and slots the two home board points we want to make.

What is the fear of burying a checker on the 1 point? You're not trying to play a priming game, but a mixed racing/blitzing type game. This means that every home board point you make is a plus.

Also, double slotting gives your opponent a 3-shot joker (34/33) that will put you back 43 pips in the race and give him some breathing room to begin to develop his position while you scramble around with four blots in his home board. Besides, being double-slotted here doesn't bring you too much closer to actually MAKING those points. You only have one spare in range to cover two points.

Right, but a la Pineapple, whenever the bots do this to me I dance and they close me out.

Hmmm, selective memory?

The thing is, the bots know the universe is rigged, and they play appropriately.

As a typical cursed human (and anyone reading this forum is hugely unlikely to be somebody blessed with luck in life) it would be an inferior move.

Gammons are activated and white has no counterplay...hit hit hit.

13-1 sweeeep.

Other than sheets, of course. And HE even likes 13/1.

No, but then I just came down with swine flu, so I have no memory, selective or otherwise, let alone the ability to calculate shots. Just unadulterated emotion and hope: "Hit those two, slot the board, close him out. Play well. Win."