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Trial and Error An interesting slam

#1 User is offline   lamford 

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Posted 2018-October-23, 08:41


IMPs Lead 9
From the Welsh trials. BBO readers get two for the price of one here, with the first problem to play 6C, after North's intelligent choice on his final call, on the lead of the 9 and the second is to play 6NT by North, on a similar auction, on the lead of the J from East.
I prefer to give the lawmakers credit for stating things for a reason. - barmar
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#2 User is offline   mikeh 

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Posted 2018-October-23, 10:04

I'm answering just as I start my morning coffee, being a little late to the office today, so my brain is hopefully going to be more efficient in a short while, but....

In 6C, we are in fine shape should trump behave. We have 12 top winners. So assume clubs do not behave.

We could try something esoteric. After 2 top clubs, play on spades, hoping to pitch a heart before they ruff in. In a perfect world someone has 4-4 blacks and they can't stop us. But spades don't rate to be 3-3, and when they are 4-2, the long spades rate to be in the short trump hand. Note that when spades are 3-3, they ruff in and play their last trump, preventing the ruff, and requiring a very low percentage red suit squeeze. I rate this way below 50%, while, against a strong player, the heart hook is close to 50%.

Leading a high spot away from the King, when one expects dummy to hold the Ace, and when one has a surprise elsewhere, is pretty standard play. It isn't clear that West can safely place the Ace in dummy, but if he has either short trump or a natural trump trick, he may well opt for the aggressive lead.

So I hook the heart.

In 6N, again there is no problem if clubs behave, so long as we don't duck the opening lead! I think that I am inevitably going to come down to the heart hook anyway, but (so long as they allow me) I will cash the diamond AK before taking the hook (obviously only late in the play so as to reduce to a 2 card ending...I go down one extra trick if RHO is brave enough to stiff his King and keep a diamond winner.
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#3 User is offline   nige1 

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Posted 2018-October-23, 12:54

View Postlamford, on 2018-October-23, 08:41, said:


IMPs Lead 9
From the Welsh trials. BBO readers get two for the price of one here, with the first problem to play 6C, after North's intelligent choice on his final call, on the lead of the 9 and the second is to play 6NT by North, on a similar auction, on the lead of the J from East.

Another good problem, lamford.

My guesses (similar to MikeH)

In 6, win A, cash A K
If are 3-2, then claim.
If are 4-1, then, cash A, K chucking a . If QJ are doubleton, then claim.
If a quack appears, then ruff a . Now If QJ drop, then cross to J, discard a on T and claim.
Otherwise cash J A K and (if those stand up) ruff a making when e.g. an opponent has 4234 shape.

In 6N, win Q, cash K, A. If s break, then play for overtricks.
If are 4-1, then discard a on the 4th .
If LHO wins and leads a then finesse.
Otherwise cash AK and your black winners -- hoping for QJ doubleton or remote squeeze chances -- but usually just relying on the finesse.
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#4 User is offline   mikeh 

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Posted 2018-October-23, 13:04

View PostHardVector, on 2018-October-23, 12:44, said:

I think I have the nt one, but I haven't worked out 6c yet. Win the club and hook the heart. If the finesse works, you have 12 tricks assuming west followed to the first club. The defense can kill it if the finesse fails and they return a diamond, but that doesn't look right at trick 3. Win the return and run the top clubs and spades ending in south. If east has the clubs stopped and west has the J, you have a double squeeze.

If they do manage to find the diamond switch at trick 3, if east has the clubs and the J you can squeeze him there. You have to cash one diamond, spades, A, then the last top diamond.


I don't understand how you create a double squeeze position if the heart hook loses, no matter what they return.

If clubs broke, you have 12 tops. When clubs don't break, and the heart hook loses, your problem is that you have only been able to reduce to 4 cards in the end-game...while you superficially have rectified the count, that isn't so because your 11th trick is the 5th club, and you can't score it without conceding a fatal trick in the suit.

There is no double squeeze in a 4 card end position with you being, in dummy, void 10 x xx and in hand void void AK10x void.

There may be a triple squeeze in that one defender has the heart J, the 4th club and the only diamond stop, but that isn't very likely. However, that is probably better than my line of conceding the club....and taking the heart hook later...I should take it right away...the triple squeeze is slightly better than hoping for QJ tight in diamonds plus I overlooked the possibility of Jx in hearts, in which case we need to get the hearts out of the way while we still have communications.
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#5 User is offline   dokoko 

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Posted 2018-October-23, 13:56

I play on nige's line but will try to ruff a diamond good even if no quack appears, so:

ruff 3rd diamond. If 10 is good, claim.
If someone showed out, try to discard dummy's heart on the spades.
Otherwise cross toJ, ruff 4th diamond, cross to Q and claim if noone overruffed the diamond or ruffed the spade.
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#6 User is offline   nige1 

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Posted 2018-October-23, 14:39

View Postdokoko, on 2018-October-23, 13:56, said:

I play on nige's line but will try to ruff a diamond good even if no quack appears, so:
ruff 3rd diamond. If 10 is good, claim.
If someone showed out, try to discard dummy's heart on the spades.
Otherwise cross toJ, ruff 4th diamond, cross to Q and claim if noone overruffed the diamond or ruffed the spade.

Initially, I thought dockoko's line would work :)
But, unless the player with 4 s has a singleton , defenders can ruff declarer's good and cash K :(
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#7 User is offline   nige1 

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Posted 2018-October-23, 15:11



In 6N on a lead, I like MikeH's triple-squeeze line.


Although when an immediate finesse loses, an inspired return might break up the squeeze.


It seems better to run s, first, discarding a

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#8 User is offline   lamford 

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Posted 2018-October-24, 05:54

View Postnige1, on 2018-October-23, 15:11, said:

[/size]

This was the actual layout. In 6C, you rise on the heart lead, cash two clubs, play ace of diamonds, ruff a diamond, cross to a top spade and ruff a diamond. Now you must play the dentist coup of cashing the ace of spades before crossing with a spade, and only now do you cash the king of diamonds and play another. If East ruffs, you overruff and play your last spade pitching the queen of hearts. If you don't find the dentist coup, East beats you by pitching a spade. If you wrongly cash a second top diamond prematurely, you will succeed on the actual layout but fail if East has only three diamonds. You need East to be 3-2-4-4 or 3-3-3-4 for this to succeed.

In 6NT you have to win the club lead, play a diamond to the ten, and win the club return and cash four rounds of spades with a progressive squeeze on East. If West inserts the queen of diamonds, you overtake and exit with the ten of diamonds (!), and East is toast again.

Players in the Welsh trials unkindly speculated that a certain Welsh player who was banned for ten years for "substituting his own packs for the ones provided by the organisers" would have had no trouble with either contract. And most people took the heart finesse, going off.
I prefer to give the lawmakers credit for stating things for a reason. - barmar
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#9 User is offline   Tramticket 

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Posted 2018-October-24, 06:51

Had to Google Dentist Coup (extracting the exit card). :)
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#10 User is offline   lamford 

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Posted 2018-October-24, 08:27

View PostTramticket, on 2018-October-24, 06:51, said:

Had to Google Dentist Coup (extracting the exit card). :)

This particular dentist coup extracts a card that East could discard to avoid the trump coup
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#11 User is offline   nige1 

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Posted 2018-October-24, 09:12


The successful lines do seem to require double-dummy play :)

In 6N, you can win the and cash 4 s, discarding a to put defenders under immediate pressure


But to succeed, declarer must still see through the backs of the cards.

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#12 User is offline   mikeh 

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Posted 2018-October-24, 09:48

I still take the heart finesse. Not only is life too short to work out the winning lines, but I truly don't think that they are the best single-dummy lines.

I appreciate the beauty of the winning lines, but this is why I rarely bother with double-dummy presentations...they are of no real benefit to actually playing hands in real life. The heart finesse is a simple 50-50 proposition, even in 6C (against a good player...against a weak player, I'd assume the finesse was off and I'd still be at the table). The actual and related winning layouts appear to me to be somewhat less probable.
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#13 User is offline   dokoko 

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Posted 2018-October-25, 00:17

View Postnige1, on 2018-October-23, 14:39, said:

Initially, I thought dockoko's line would work :)
But, unless the player with 4 s has a singleton , defenders can ruff declarer's good and cash K :(

You're right - didn't think it throügh.
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#14 User is offline   nige1 

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Posted 2018-October-25, 07:27

View Postdokoko, on 2018-October-25, 00:17, said:

You're right - didn't think it throügh
None of us seem to have thought it through, successfully :(
But Dokoko's line in 6 is close to the winning double-dummy line, if only 2 top s are cashed, initially.
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#15 User is offline   rhm 

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Posted 2018-October-26, 11:59

View Postlamford, on 2018-October-24, 05:54, said:

...
You need East to be 3-2-4-4 or 3-3-3-4 for this to succeed.
...

Works also on 4-2-3-4

Rainer Herrmann
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#16 User is offline   lamford 

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Posted 2018-October-27, 10:32

View Postrhm, on 2018-October-26, 11:59, said:

Works also on 4-2-3-4

Rainer Herrmann

Or 4-1-4-4 with or without the king of hearts. That might be enough to swing the play in favour of rising at trick 1, and drawing two rounds of trumps, especially as I think the heart lead from Kxxxx(x) is unlikely. It might let through a no-play slam when dummy has Ax(x) of hearts opposite Qx(x).

I investigated this some more. Finessing the heart, assuming that the opponents will always lead a heart with or without the king, works about 80.4% of the time, whenever the heart finesse is right and clubs are not 5-0, and also when clubs are 3-2 and there is no heart ruff.

I think that rising with the ace of hearts is clearly right. That works in the following cases:

a) Clubs 3-2: 67.8%
b) Clubs 4-1 and QJx or QJ tight in diamonds in either hand: 2.9%
c) Clubs 4-1 and diamonds (otherwise) 4-3 with 4-club hand having 3 or more spades 9.78%

This totals pretty much the same, 80.48%, and is slightly better even against Gabriel and Jophiel who will unerringly lead a heart with or without the king to give you a losing option. Actually, against those two miscreants it does not matter what you do - if you rise with the ace it will be ruffed and, if you finesse, East will win and give his partner a heart ruff.
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#17 User is offline   gszes 

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Posted 2018-October-29, 15:21

An interesting side thought about the 6c contract -- assuming you could do all of the math in your head in a short time and realize the chances of making your contract via the elegant squeeze vs the pedestrian finesse is about 8 100ths better, a difference so tiny it is essentially a toss up, -- It STILL looks to me like the finesse is better because it allows us to make 7 and pick up an IMP half of the time. GO MIKEH
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#18 User is offline   lamford 

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Posted 2018-October-29, 19:01

View Postgszes, on 2018-October-29, 15:21, said:

An interesting side thought about the 6c contract -- assuming you could do all of the math in your head in a short time and realize the chances of making your contract via the elegant squeeze vs the pedestrian finesse is about 8 100ths better, a difference so tiny it is essentially a toss up, -- It STILL looks to me like the finesse is better because it allows us to make 7 and pick up an IMP half of the time. GO MIKEH

That is not the case. You will make seven when clubs are 3-2 and the diamonds are 4-3, regardless of how the spades break, and wherever the king of hearts is. So you actually make an overtrick MORE often by rising. And you look pretty stupid when the heart loses and they get a heart ruff with the clubs 3-2 all along. GO get your coffee MIKEH.

In 6NT, I think you just test the clubs and then finesse the heart if they don't break. The winning line there does look through the back of the cards.
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