Thin 6NT

[gnasher]

[hv=pc=n&s=s63haj975dq9cakt6&n=sakt97hk6dak6c954]133|200[/hv]

 

You reach 6NT after 1♠-2♥;2♠-2NT;4NT-6NT. (Yes, I know you might have bid it differently.)

 

LHO leads ♣Q. Plan the play.

[Fluffy]

My thoughs are:

 

The suit that might provide 3 tricks more easilly is hearts, if we play a heart to the jack and it wins, we have a lot of options even if hearts are 4-2, we can try for 4 spade tricks fore example before commiting to hearts.

 

But if ♥J loses then LHO switches to spades, and now we must rely on some squeeze and hearts breaking 3-3. We are in very bad shape, and LHO´s switch makes us lose the option of ♠QJ onside.

 

A losing ♥J puts us in very ackward scenario. Messes comunications a bit and loses options around the way.

 

Its better to just go and think ♥J is onside and go onwards from there. We have then 10 top tricks and need only 2 more. Those can come from hearts 3-3 or spades coming for 2 extra tricks. And the way to combine these chances is to play a spade to the 10 at trick 2.

 

If ♠10 wins we don't even need ♥J onside, its true that losing to ♠QJx offside might go down when the contract was makeable but you can't have it all. After winning the club return in hand we cash diamods discarding a club from hand and try 3 rounds of hearts. Squeezing west in 3 suits if he has ♠xxx ♥10xxx

[han]

I didn't understand Fluffy's post so let me go through the calculations myself. I'm going to assume that LHO has QJx(x) of clubs.

 

Line A: Take the heart finesse first. If it wins, play on spades. If it loses, hope that hearts run and that LHO is squeezed.

 

Line B: Play on spades first. If you get lucky with QJx, claim. If the spade finesse loses, win the return and finesse hearts. If it loses, down. If it wins, try to run the hearts and fall back on spades if that fails.

 

When the heart finesse wins both lines are equal. When spades are QJxx onside and the heart finesse fails both lines are equal as well: you'll make on a squeeze when the hearts run.

 

When the heart finesse fails, line A wins over line B when hearts run and LHO has 4+ spades but not both honors, but line B wins over line A when LHO has QJx of spades and the hearts don't run.

 

To simplify matters I'm going to restrict myself to the cases when RHO has at least 2 hearts. When RHO shows out on the second heart the two lines are roughly equal.

 

The chance that the heart queen is offside and the hearts don't run is about 16.149%. The chance that QJx of spades is onside is about 7.1056%. So Line B wins over line A about 1.1475% of the time.

 

The chance that the heart queen is offside but the hearts run is about 26.646%. The chance that LHO has 4+ spades but not both honors is about 16.9565%. So line A wins over line A about 4.518% of the time.

 

Of course different suit-breaks are related so my calculations are incorrect. However, I found that line A is so much better than line B that this is probably still ok.

 

I found a different answer from Fluffy's so I'd better reread to see if I did things correctly.

[han]

Having reread (and edited) my post and having reread Fluffy's, I think Fluffy underestimated the squeeze chances by a lot. If we assume that LHO has the jack of clubs (not unreasonable given the lead), then the squeeze is automatic whenever LHO has 4+ spades or QJx, as long as the hearts run. We don't have any communication issues.

 

The squeeze is a lot better than finding exactly QJx of spades onside when the hearts don't run.

 

Given that the chance that hearts run is larger than the chance that hearts don't run (in the relevant cases), I seems really clear to play on hearts first.

[Fluffy]

I though that when ♥J losed and LHO played a spade you had to give up on spade QJ onside. You have to bank all in ♥3-3.

 

What I realice now is that ♥3-3 (or doubleton 10) is pretty good, you have an automatic squeeze then. So playing for hearts to provide 4+ tricks not touching spades is better, and my earlier post os wrong. I though losing to ♥Q put us in a very bad position when it indeed doesn´t, just needs LHO to hold ♠QJ or 4+ spades. If he underleads ♠QJx it will go down when hearts don't break it will go down, but that's the only lose I think.

[han]

Yeah the slam is not so thin after all. :)

[whereagles]

This seems simple: heart finesse and take it from there :)

[Fluffy]

next question is if ♥J holds, if its better to

 

-play spade to the 10, then test hearts, then finese spades if needed.

-cash ♠AK and if no honour falls, then ♥A and if hearts arent 3-3, fall back to spades 3-3 with the ♠Q not having 4th heart.

 

EDIT: we don´t have enough transportation to test second line, so can't try for it.

[AlexJonson]

Without aiming to challenge the conversation so far, it is not been mentioned that if you play on spades first,

 

- you may find that RHO almost certainly had a singleton club if he wins the first spade and doesn't return a club

 

- you may make three spade tricks (three only) without loss and choose from there (setting up a fourth spade or playing hearts)

 

- if you set up four spade tricks, you can delay a decision in hearts - finessing against RHO versus squeezing LHO

 

Probably not sufficient to outweigh the technically correct line, depending on your belief in your card reading.

[mikeh]

I think the odds on playing on spades are a lot closer than others have suggested.

 

I admit that the odds of spades playing firstly for 5 tricks and secondly for 4 tricks are, in both cases, well below the figures for the heart suit.

 

But if hearts play for 4 tricks we need LHO to hold 4 spades. Assuming a reasonable diamond break, that seems unlikely...ignoring QJ tight in clubs, where it doesn't much matter which major you attack....you will eventually stumble into 12 tricks most of the time....he has 3/4/5 clubs, 2/3 hearts, and some diamonds.

 

If spades play for 4 tricks, we can afford to cash the minor winners before turning our attention to hearts. Thus if LHO shows up with 4 spades, at least 3 clubs, and at least 3 diamonds, we can take the heart hook.....the worst it will be is 50% and it might be 100%....LHO being 4=1=4=4 or 4=1=3=5.

 

otoh if spades were 3-3, and LHO showed out in diamonds with rho showing in to the top clubs, we'd have a 100% line by a club-heart squeeze on LHO....he'd be known to hold at least 4 hearts, so in the end game hearts would be 2=2 or 2=1...the club 9 is the club threat in dummy.

 

He will hold short diamonds about 10% of the time.

 

Our problem in hearts is that the hook of the J will lose about 50% of the time and a good LHO will return a spade on many of those occasions...and now we can't test the spades...we have to commit to the club-spade squeeze on LHO before we know the odds that he has the squeeze holding. By playing on spades, while we reduce our odds of an immediate win, we increase our odds of reading the end-position correctly....because we have two ways to play hearts and can choose in the endgame.

 

I can't do the math...I suspect I could, armed with an odds table, but I can't be bothered.

 

I suspect that the heart attack is slightly the better but I don't think it is as clear as others have suggested.

[han]

...

[Lurpe]

deleted - error logging in -

[phil_20686]

I think there is more to the lead than people have suggested - leading from QJx or QJxx vs 6 NT is no very common IMO, It will give away a trick any time the opposition hold the HTx on your left, which is quite significant.

 

I think that its therefore really quite likely that either lho holds long clubs, say five or six, or that he holds worse holdings to lead from in the other suits.

 

 

Given that I think lho would lead from xxx spades here instead of QJx or QJxx in clubs virtually automatically, I think a spade honour onside seems hugely likely. Finding Hx Hxx or Hxxx onside in spades seems pretty good odds to me. I would take the double spade finesse hoping for four spade tricks and delaying the heart decision. If rho turns out to have two or more clubs, I will refuse the heart finesse and play a club heart squeeze vs lho.

[gnasher]

At the table I played ♥K, heart finesse. When that held, I tried a spade to the 10, which lost. East returned a club, as expected.

 

The downside of this line was that the club return took away my squeeze chances - I couldn't cash the diamonds before playing ♥A. So, I cashed ♥A, LHO showing out, then took another spade finesse. That won, but LHO had Qxxxx xx xx QJxx, so I was still one down. If I'd been allowed to cash my diamonds, LHO would have been squeezed, and I'd also have had a complete count so I'd have known it was right to take a second spade finesse.

[Fluffy]

bah han I hate you, you convinced me away from the winning line, I will never listen to you again :P

[JLOGIC]

At the table I played ♥K, heart finesse. When that held, I tried a spade to the 10, which lost. East returned a club, as expected.

 

Seems like RHO will frequently have a stiff club given the lead. I don't think QJx would be an attractive lead for LHO against a quant no fit 6N auction, so if LHO will have 4 or 5 clubs there must be a reasonable chance RHO will have no club to return (especially if you view LHO as more likely to lead from QJ8xx than QJ8x or QJxx (not sure if this is true.).