Problem of the Week #17: June 28


Cash Game. White owns the cube. Black on roll.




Black to play 6-1.

im pretty torn between 20/14 8/7 and 9/3 14/13 since i feel like black wins a gammon most of the time even without making the 3 point, but i would think making the 3 point significantly cuts down on the chances that black ends up leaving a shot. and even if white enters and hits, he's going to have a real hard time getting all 4 checkers up to the 3 point then rolling 4 6s, unless he gets a miracle like 22.

so i guess i go 9/3 and then 14/13 since it makes 22 a little less crushing, altho im not even sure if white should play 22 as bar/2 1/3*(3) or bar/2 1/3*(2) 12/14* if black left the blot on the 14pt

I would probably play 9/3 8/7. This gives black maximum chances of rolling forward his 5 prime or creating a 6 prime in front of white, while the risk is relatively small. I think activating the builder on the 8 point is more important than lessening the severity of a 2-2 joker from white. (Also notice that 1-1 becomes stronger for white if you play 14/13, so this offsets some of the benefit.)

I think making the outfield point is too conservative in this position. Black has a license to play fairly aggressively with his superior board and the fact that many of whites checkers are caught behind a 5 prime, and so I think he should.

14/7. I guess, I could be talked into the safe 20/14 8/7, but I like that extra builder for the 3 point.

You're such a favorite to win at this point that you should be looking at winning gammons. I slot because I don't think you hurt your winning chances very much if he happens to hit you on the next roll, but it's a massive victory if you slot and he dances (or otherwise fails to hit you). So 9/3 happens first.

Playing 8/7 buys you an extra builder because you don't mind leaving a blot on the 8 point to make a home board point when your opponent is on the ace point.

9/3 looks mandatory to try to win gammons. You'll even be able to win some backgammons. As for the 1, I guess 8/7 is slightly better than 14/13, I can't imagine it mattering very much.

if this is cashgame with cube in the middle and assuming jacobyrule,then you will be able to turn the cube and get a pass if you play safe and allow no jokers for the opponent.so 20-14 and 8-7 or 6-5 or even 9-8 will get the job done.

You'll be too good to double.

not with jacobyrule!

jacoby rule is for nits

the only way black won't be guaranteed to have a double next turn is if he breaks up his prime by moving 5/4 4/3 or 7/6. i mean, even if white enters and hits next turn if black slots, im pretty sure black could still double from the bar and white would have to pass if his prime were still intact

I didn't read the words. I just looked at the picture. The picture is white owns the cube. I don't think it changes my play.

My apologies. The picture is correct. White owns the cube.

Yeah, I'm pretty sure that's a typo in the OP. This isn't all that interesting if the cube is centered (and how did black get this far without cashing anyway).

Been so long...so long indeed. Since that completely counterintuitive "New Ideas in BG" book I really lost track of theory.

But I would day that 20-14/8-7 has to be best here, although pretty much anything is good in this spot as white is completey bottled up with no timing to even pray for any kind of back game at all.

As a matter of fact, I think that's why the slotting variations are going to be worse. Black has white so destroyed here that he doesnt want to provide too many variations for white to obtain any kind of game at all.

If this isnt a 2.00 equity spot, it has to be pretty close....

Does Jellyfish still exist anymore or has snowie just bankrupted it?

one thing is constant whether it be poker or backgammon; sheets is a nit

If I got into this position in a tournament I would move 14/7 in a second. I really can't find alternatives that makes sence to me.

I see black winning by killing whites timing which for me rules out 20/14. Now slotting the 3-point is kind of tempting but I don't want to be tempo-hit giving white fair chances to anchor up. By playing the silent 14/7 we keep our prime, activate another builder, keeping a checker back to stop white from doing whatever he like.

Looking forward to the solution (and possibly a learning experience).

I think that's reasonable, but black isn't just trying to win the game, but also to win a gammon, which is a consideration that argues for slotting. Either this or the slotting play could be correct, though.

This reasoning makes no sense at all. You're basically saying that if you're 95% to win a game, then it's worse to drop down to 90% than it would be if you were 50% to win a game and dropped to 45%. The only things that matter in analysing the move are how much it changes your game winning chance and how much it changes your chances of getting a gammon/backgammon. How much you're already crushing White is irrelevant.

Not what I am saying at all.

I was just assessing that this position is ridiculously crushing and in this particular spot, slotting allows too much counterplay.

I would be very surprised if any slotting option rolled out better.

Depends on match score

True, but in my experience the way to win most gammons is to prevent white from getting another anchor and keeping him from trying to get a well timed acepoint game.

The interesting thing about slotting the 3-point is that it's more volatile but not nesseary wrong. It help us make our board faster but still I don't think it follows what I see as "the game plan".

I'm beginning to get very tempted to put it in the computer to see if there seems to be a big equity difference between the ideas.

This is kind of the idea....I don't think he loses too many gammons by not slotting. Playing this position solidly and watching white completely crash will lead to enough gammons at very very little risk of losing. I can tell you that if I were white, holding the cube, I would be happier seeing a road to victory created by a slotting variation.

I could be wrong, but I think the best way to prevent white from getting a 2nd anchor is for black to extend his prime forward, and unless he rolls a few perfect numbers the only way he's gonna do that is by slotting. and you might as well slot now when it's no big deal if you get hit

I agree with this. White wants the 3 point to stop you from rolling your prime. By slotting, you give yourself the best chance of making it. You need to roll pretty well to make that point in a single roll (even if you have lots of builders lined up).

Let's say you moved 14/7, giving yourself 4 builders for the next roll. Then assuming he doesn't make the point first you make the 3 point with 63/53/43/64/54/65, and you would probably break your prime to make the 3 point when you roll 22/44 as well. That's 14 rolls.

Now let's say that you slot it with 9/3 8/7. Now the math is a bit more complicated because when he enters with a 3, you're going to enter and likely have a chance to hit back, but this is almost a push (slight edge towards your opponent because even though you still have builders, you have one less of them). But let's just suppose he doesn't knock you off the 3 point. Now you make the 3 point with any 3, and 4, and any 5, plus 11/21/22 for a total of 29 rolls. That's more than double what you otherwise would have. I think there's enough of a buffer there to account for those times that he sends your checker back.