Problem of the Week #80: October 17


Cash game, center cube. Black on roll.




Should Black double? Should White take if doubled?



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.

Yes and yes.

Double seems obvious. You're well ahead (30 pips and structure and 5-pt anchor), and the gammon chances are quite asymmetric, so I can't possibly see how you don't double here.

The take question is trickier for me. Obviously black has some rolls that just blow you up (11/31/44), as well as some other productive ones like 66/21/32, but when that doesn't happen, it's hard for white to get home cleanly. White is left with enough timing that clearing the 20 is going to be annoying without doubles, and if he can anchor on the 5, he gets something i would call a double holding game (against the 13 and 20) with a decent bit of timing and the cube.

If you anchor on the 5, or he hits loose and you rehit, you have a quite playable game. The worst-case scenario is getting blasted back into a kind of bad 1-point game.. which isn't THAT bad in reference to the take point. You seem to get a mix of 15%ish positions and 40%ish positions, with more of the 40%ish positions, which means you should be able to find a take here.

Double/take.

Easy double. Lots of rolls make the 5 point (11, 22, 33, 44, 21, 31, 32 for 12 rolls -- yes, you should sacrifice the bar point to make the 5 point). Even hitting loose followed by a dance might lose the market.

I can't see dropping this one. 12 rolls may make the 5 point, but this means that 24 rolls don't. If black hits loose, white might hit back and bring the race quite a bit closer. And if black doesn't hit loose and doesn't make the 5 point, white might make the 5 point anchor and be in decent shape because his outfield structure is better.

Black is way ahead in the race (143-175), has a better structure, less men back, a better anchor and moderate gammon threats. The double seems obvious.

Now, as White, I would be worried. Holding the golden point, Black won't hesitate to hit loose, especially when White has no board yet. 3-1, 4-4 or 1-1 would be disastrous for White, with 3 checkers stuck behind a 5-prime. I think I would drop this one.

Double / Drop

Double is clear.

I think this is a drop, and the theme of the position is that it's tempting to take because IF you make the 5-point, you'll have a reasonable game.

The thing is, that's a pretty big IF, because Black can feel free to fire away. As White, even if things go your way, you will still be a dog. Meanwhile if things DON'T go your way, it's gonna get ugly.

As a comparison position, move the 5-point checker to the 12-point. Even though White has gained in the race and has a safer position, there is really no reason at all to consider taking a double. The fundamentals of the position are just too poor. Now, from that position, move the checker back to the 5-point. Would anyone think the resulting position (we're back to the original one now) is actually an improvement over the comparison position? If not, well, the original has to be a drop as well.

Double/take. As others have pointed out, I think the double is the easy part. As for the take, in addition to echoing the sentiments of other posters, because black is up 30ish pips, he will have to break the 5-anchor in the not-so-distant future. If he leaves with one checker, white can try to attack the lone black checker. Also, when black hits loose (which he, of course, will) white will have return shots to equalize the race and reslot the high anchor with tempo.

Black is not a big favorite here but I think a double is OK. If black waits to double and rolls 1-1, 3-1 or 4-4, he loses his market immediately. Even 3-3 is still pretty good but it that case, white might have a take.
White has a very clear take. He might make the defensive 5 point next roll. Right now, black has very few gammon chances because of white's anchor.

Answer - double/take

One thing I'm pretty sure, the double is clearer than the take.

The fight for the five is going to be the next skirmish and with 22% market losers, close to 60% of blacks numbers hitting loose and a great anchor this is a clear double.

In spite of all this I would take as white, I can’t see jumping out yet. Great things can happen if you exchange some hits.

Double/take

Should Black double?
NO (black can wait a few rolls or hope white doubles)

Should White take if doubled?
YES (beaver it)

Grunch.

Double and take in a shot. But why? And how over the board? In the ICU, we work with bundles and try to execute our basics with excellence. One of my favorite papers on that topic is “Give your patient a fast hug (at least) once a day”. Here, Mr Vincent introduces the Fast Hug mnemonic (Feeding, Analgesia, Sedation, Thromboembolic prophylaxis, Head-of-bed elevation, stress Ulcer prevention, and Glucose control) as a means of identifying and checking some of the key aspects in the general care of all critically ill patients.
My mnemonic for the general care and feeding of the doubling cube is PratPac9.

Will i be a prat to ship it over? Can i be PacMan and eat this? Is there a strike?

Prat stands for position, racing advantage and threads. Better front position, golden point, fewer men back. Solid racing lead. Thread to make the 5 point. A yes in every direction. Double must be clear.

Bill spelled out in the problem of the week his rule of thumb for a take decision. For mnemonic reasons i call it for myself PacMan. Has your opponent a 5prime? Have you an anchor? Is there still contact on the other side of the board ? If you have on first no and the two others yes, then take is clear. Otherwise, you have to look closer.

Strike. Because volatility is a difficult thing to measure, i look with a treshhold on the position. If i have 9 clear outs, then i have enough volatility to hit myself seriously if i delay the double. If there are numbers, who make me worse, i decal them. 10 numbers will make the 5 point. Decal the hits after making the 5 point, leaving a blot on the bar point, i will have my 9 outs. Otherwise no sequences, that will leave me worse.

Therefore again: double, and take.

Then I would raccoon you in a heart beat.

After reading the other posts there is a general opinion, that the double is trivial and the take decision is difficult. Beside Bills rule of thumb: Owning the 10 point is a pretty big asset for white. I remember the times in my youth, when i played chess. There was an attempt to classify openings after the pawn structures. Because pawns cannot move freely, they are soon fixed and build the structure of a position. It is a little bit like anatomy. In backgammon, there are the key points. Sceleton down whites position. What has to stay as a defense against the golden point? The 10 point. So 8 men to play with. Pretty much time. Meanwhile white can fill his board. If black isn't able to throw doubles, to connect the golden point to the main corps of the troops, there will be attack. Regardless the priming situation. And black, if we sceleton, has only 3 to 5 free men. So looking in a dynamic way, for me the golden point is still the golden point, but with a janus head and also a well for later accidents.

WoW! So let me make sure I'm figuring this right. I would be White in this a cash game, it would be your roll, and i would possess the cube at 8.

In light of the analysis that's been posted here, I have to agree. I didn't realize white's position was so weak. I still take here but I'm not as happy about it. I still don't see how it can be correct to drop in this spot, though.

Can we play for money?
You think white might been in a position to double in a few rolls and you'd beaver if you were doubled?!
I would be interested to find out what you think is so good about white's position.

I really don't get how so many people are taking this cube.

Black is way ahead in the race, but not SO far ahead that White has any realistic backgame prospects.

Black is one good roll or sequence away from a 5-prime with (at least) two White checkers trapped behind it.

Black owns White's 5-point.

Black has his sights set on a White blot sitting on his own 5-point just waiting to be attacked.

White... um... has the 10-point. OK, yeah, it must be a take then.

If im ever around and your there and i get back into it i would love 2

I was trying to say that as black i would wait and hope white doubles, if black doubled and i was white yes i would beaver. (is that what you meant)

After Bills answer i would say more if i have the time and writing ability or Bill does not say it. For now i would say there is lots of game left in this position and possession of the cube with an higher than opening value in a cash game has some value i think.

There's a lot of stuff that can happen, and not all of it is bad for white.

I don't think white is looking to play a backgame from here. I think a deep defensive anchor is the most likely situation, but it could easily turn into a 5-point anchor. The timing isn't so bad unless white happens to end up with all three checkers stuck on the ace point or something like that, but there is usually going to be enough time to avoid that scenario.

Only 31 and 44 create the 5 prime (33 is also a strong roll because even though it gives up the 8 point, white is too deep for that to be a real problem). 21 and 23 both leave the bar point open for an attack (10 shots for white coming off the bar, plus white will have chances to make an advanced anchor), and 22 gives up the bar point. Also, black hitting loose gives white more openings to get back in it. This is a volatile situation, but there are swings in both directions.

At this point, that's not really an asset for black. Black will need to release those guys in the next couple rolls.

Except for a few rolls, black opens up a point of weakness when he makes the 5 point, and if he hits loose, white has a good number of returns that hit back (5x, 41, 23, 24, 34 = 19 shots > 50% of the time).

I don't get that one, either.

That's exactly it!

At first blush this looks lika a cube and a drop.

The cube seems obvious, the drop less so.

Pineapple in his first response did a good job explaining why it's a drop.

Upon closer examination, I now think this is a take. I think Aaron has done a good job (as usual) explaining why it's a take and I have nothing to add to his explanation.

Perhaps the flaw in Pineapple's analysis is that the blot/slot? on the 20 point is an asset, rather than a liability?

TBH if this happened in a game situation, I would probably have dropped. The fact that this position appeared here as a problem always gives pause though and makes me take a closer look.

Another great problem anyway.

White would have to get very lucky to be in a position to double. By the time white does double, black will no longer be happy about getting doubled because the position will be drastically different.
This already looks like it is a strong double for black and white has at most a thin take. Some people here would even drop this. So, I don't see the point in waiting.
A beaver by white looks like a huge mistake. You need to go back and recalculate what white's winning chances are (his gammon chances are close to 0% now). Owning the cube is not nearly enough of an advantage to beaver here.

BTW, so far, there has been only one problem where the answer was no double/beaver. That one was a very interesting position and it was also very different from this one. Bill's positions tend to be tough decisions where it is a choice between double/take and double/drop.

Hi,

i will try to compare the position with beter known positions (to me), say for instance there was one checker on the bar,
instead of two on the ace-point, then the situation would be double/pass, because of the high anchor and the 6 attackers.
So black is now still the favourite in the blitz against the 5-point.
White will most probably end up with a low anchor against a 4- or 5-prime, the direct chance of getting the 5-anchor is:
8/36 (no hit on the 5) * 14/36 (white throws 4) = about 9%, besides that a normal ace-point game would give white
about 15%, but with an extra checker there will be gammons, and the play behind a 5-prime has the chance of extra checkers
back because of possible bad 3, 4, 5 and sixes, so the total chance of white will be less than 24% so I would say double pass.

Weird, that's the only thing that makes any sense to me.