[akwoo]

You are South. The opening lead is a small spade. You see

---

and you are about to congratulate yourself on reaching 7NT when LHO shows out on the second diamond.

How close to a 100% line can you get?

What if RHO shows out on the second diamond? (In this case, I'm pretty sure there is no 100% line, but there might be one better than just hoping for either the spades to split or defenders to mess up.)

[manudude03]

This will probably take some table feel, but I cash the other 2 diamond winners throwing a spade and a club. RHO would have to make 3 discards.

There are too many ways this can go and it's late for me, but I'll probably end up playing 3 rounds of spades throwing a club, 2 rounds of clubs making the contract unless RHO started 2-7-1-3 (and not both club honours).

The opponents are very likely to tell you if you need to play differently though.

[rhm]

akwoo, on 2014-October-21, 19:24, said:

You are South. The opening lead is a small spade. You see

---

and you are about to congratulate yourself on reaching 7NT when LHO shows out on the second diamond.

How close to a 100% line can you get?

What if RHO shows out on the second diamond? (In this case, I'm pretty sure there is no 100% line, but there might be one better than just hoping for either the spades to split or defenders to mess up.)

Let me tell you that I dislike when a play problem is given with less information than would have been available at the table up to this point.
Why do we not get the bidding?
Why do you think it is enough to tell us that the opening lead is a small spade instead of telling us which spade was led, where it was won and which card RHO played?
Why do you not tell us which card LHO discarded, only telling us he showed out?
You might think this information is irrelevant.
Well in this case we might as well consider your problem irrelevant.

Rainer Herrmann

[ahydra]

Huh. I wanted to downvote rhm's unnecessarily aggressively-worded post but apparently I've "reached my quota for the day". (I guess the quota is zero.)

He does have a point though - knowing the spade that was led (in context of EW leading style) and what the discard was would be very useful.

Hopefully we won the spade in hand. I am looking for a black-suit squeeze against a West holding Jxxx xxx x QJxxx or similar, where after four diamonds and then three hearts he has no chance of guarding both. Or maybe if both opponents guard clubs there might be a double squeeze with East being squeezed out of his diamond length and West his spade length, something like

West Jxxx xxxxx x Qxx
East 10x xxx 10xxxx Jxx

On 4 rounds of diamonds West throws three hearts. Now three rounds of hearts where West is squeezed - let's say he throws a club. So we cash two more rounds of spades ending in hand and East must throw a club. Then the AK of clubs crashes the QJ. I think I like this line better, not just because a non-simultaneous double squeeze earns many style points, but because West might have led Q from ♣QJxx (well, perhaps - depends on West's skill level).

I suppose the best defence to this is for West to chuck a small club on the second diamond

ahydra

[Fluffy]

ahydra, on 2014-October-22, 06:39, said:

Huh. I wanted to downvote rhm's unnecessarily aggressively-worded post but apparently I've "reached my quota for the day". (I guess the quota is zero.)

You are not the first one.

[manudude03]

ahydra, on 2014-October-22, 06:39, said:

Huh. I wanted to downvote rhm's unnecessarily aggressively-worded post but apparently I've "reached my quota for the day". (I guess the quota is zero.)

He does have a point though - knowing the spade that was led (in context of EW leading style) and what the discard was would be very useful.

Hopefully we won the spade in hand. I am looking for a black-suit squeeze against a West holding Jxxx xxx x QJxxx or similar, where after four diamonds and then three hearts he has no chance of guarding both. Or maybe if both opponents guard clubs there might be a double squeeze with East being squeezed out of his diamond length and West his spade length, something like

West Jxxx xxxxx x Qxx
East 10x xxx 10xxxx Jxx

On 4 rounds of diamonds West throws three hearts. Now three rounds of hearts where West is squeezed - let's say he throws a club. So we cash two more rounds of spades ending in hand and East must throw a club. Then the AK of clubs crashes the QJ. I think I like this line better, not just because a non-simultaneous double squeeze earns many style points, but because West might have led Q from ♣QJxx (well, perhaps - depends on West's skill level).

I suppose the best defence to this is for West to chuck a small club on the second diamond

ahydra

West has 5 diamonds, it was East who showed out.

[nige1]

akwoo, on 2014-October-21, 19:24, said:

You are South. The opening lead is a small spade and you are about to congratulate yourself on reaching 7NT when LHO shows out on the second diamond. How close to a 100% line can you get?
What if RHO shows out on the second diamond? (In this case, I'm pretty sure there is no 100% line, but there might be one better than just hoping for either the spades to split or defenders to mess up.)

---

I like manudude03's line.
When you test ♦ and ♠ you can claim unless the same defender holds length in both. When the same defender controls both suits, you might have a compound squeeze if you can guess his shape. Otherwise, if you're not good at guessing ...
You can reduce to this 4-card ending.
This line succeeds unless
one defender keeps 4 ♥s. while
the other can retain winners in ♠, ♦ and ♣
e.g. it fails if a defender is 4153 with a ♣ honour.
.

---

[johnu]

ahydra, on 2014-October-22, 06:39, said:

Huh. I wanted to downvote rhm's unnecessarily aggressively-worded post but apparently I've "reached my quota for the day". (I guess the quota is zero.)

He does have a point though - knowing the spade that was led (in context of EW leading style) and what the discard was would be very useful.

I don't see anything wrong with rhm's post. Maybe he didn't have his cofffe this morning but I can't disagree with anything he wrote. If readers are going to take several minutes (or maybe much more) to respond, the original poster has a responsibility to make sure the details are complete and accurate the first time. The details are woefully incomplete in the original post. In this case, the discard by LHO on the 2nd diamond may have a big effect on your line of play but we don't know what it was.

[Lovera]

I think should be preferred to use West or East instead LHO and RHO.

[akwoo]

Follow-up from the OP:

1) This is a hypothetical problem. I saw the hand in question, but neither bid to 7N nor saw a bad diamond split. I just thought it was interesting afterwards.

2) I agree that, at the table, one is going to have clues from the opponents' carding, et c. My original curiosity is about the mathematical problem of finding the 100% line (which does NOT depend on the opponent's carding, since 100% means it should work even when opponents lie) if there is one. Of course y'all can go ahead and try to answer the bridge question under various hypotheticals, but I have no further actual information since it's a hypothetical problem.

[manudude03]

The thing about this hand is it is virtually impossible for the opponents to "lie". If East throws 2 hearts, then you will know who has sole guard of hearts by cashing AKQ of hearts. If he throws 2 clubs, you can test who has sole guard of clubs by cashing 2 clubs. And finally, if he throws a spade, you can cash a spade to find out the spade situation. Hence the best line is going to depend on their discards.

[Lovera]

Let's talk about shape : when we have in West 1) ♠ 2-4-5-2 in East there is 4-4-1-♣ 4; 2) in W 2-3-5-3 in E 4-5-1-3 ; 3) in W 3-3-5-2 in E 3-5-1-4 ; 4) in W 3-4-5-1 in E 3-4-1-5 ; 5) in W 4-4-5-0 in E 2-4-1-6 ; 6) in W 4-1-5-3 in E 2-7-1-3 ; 7) in W 4-2-5-2 in E 2-6-1-4 and we can see that with shape 3) and 4) whatever opp discarding we have 13 tricks , shape 5), 6) and 7) are less probable than i consider only shape 1) and 2). Whit shape 1) East have a free discarding in club whilest with shape 2) in heart but on another diamond take to be unilateral heart or club than rescouting top spade and high cards in suit of discarding of East we realize a balanced double squeeze on last diamond. I think that probable shape in West considering opening leads be 2), 3) and 4) ( lacking bidding for ultherior indication).(Lovera)

[FrancesHinden]

I think it's entirely reasonable to ask if there is a 100% line. As he says, if there is then you have sufficient information to answer the question.
When East has the long diamonds it's certainly cold double dummy. My guess is that it isn't when West has them.

Single dummy is a more interesting challenge.

[nige1]

FrancesHinden, on 2014-October-25, 05:54, said:

I think it's entirely reasonable to ask if there is a 100% line. As he says, if there is then you have sufficient information to answer the question. When East has the long diamonds it's certainly cold double dummy. My guess is that it isn't when West has them. Single dummy is a more interesting challenge.

On a ♠ lead, I think the contract is makeable, at double-dummy, no matter how the cards are distributed between defenders. I can't find a counter-example.