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Snatching at Straws Poor 3NT

#1 User is offline   lamford 

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Posted 2020-July-23, 17:15


Div 1 of a National League. South leads the two of hearts (fourth) and North plays the four, which is reverse attitude or reverse count, this exact situation undiscussed. Over to you. Sorry, I left out the auction: 1C-1D-1S-2NT-3NT uncontested.
No, I meant exactly what I wrote; I believe BBO's claiming algorithm is about as perfect as it can get. It's basically the only aspect of GIB that I find faultless. - smerriman
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#2 User is offline   KingCovert 

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Posted 2020-July-23, 17:59

Well, it seems like I must lose 3 hearts and the A. Hearts should be breaking 4-4. It's a little unclear to me which player should hold two honours. I can't imagine that South underlead KQJx, but, I think, to this auction, they could have underlead pretty much any combination of two of those honours, or simply just Qxxx or Kxxx.

Luckily for us, we don't really have to guess.

1) A.
2) K.

If opponents win the A, then they should now draw hearts revealing the honour situation. I will now pay attention to which player had the A and see if they have two heart honours. If so, I'll play the other player for the Q. If not, I'll play the player with the doubleton diamonds for the Q.

If the opponents don't win the A. Then: Q, and much the same logic.

If the opponents don't win either of the first two club tricks. Then: I will play to take 9 tricks off the top. Cash the AK checking to see if someone has QJ double-ton. Probably not the case. I'll play the player with the doubleton diamonds for the Q and try to collect the spade suit for 0 losers.

I think it's likely spades are breaking 3-3. I may have to reconsider this assumption if I have the opportunity to play 3 rounds of clubs at some point (I won't have it if I can't draw the A in the first two rounds of clubs) and someone shows out on the third round. Now it's a guarantee that spades are breaking 4-2, but, the player with 5 will have the doubleton spade. (Provided that the hearts are 4-4, which *seems* certain)
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#3 User is offline   Vampyr 

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Posted 2020-July-23, 19:56

The past tense and past participle of ďleadĒ is ďledĒ. This weird error has recently crept out of BBO and entered the wider world.
I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones -- Albert Einstein
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#4 User is offline   lamford 

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Posted 2020-July-24, 15:05

View Postlamford, on 2020-July-23, 17:15, said:


Div 1 of a National League. South leads the two of hearts (fourth) and North plays the four, which is reverse attitude or reverse count, this exact situation undiscussed. Over to you. Sorry, I left out the auction: 1C-1D-1S-2NT-3NT uncontested.

The only winning line in theory is to cross to a diamond, play a club to the jack and duck a club. You only have three spade tricks, and the opponents should not oblige by cashing the hearts if you play another high club, as South does then get squeezed in the pointed suits. I tried the ten of diamonds en route, but no singleton nine appeared! I made a very poor stab at this, and think your line is best except against world class defenders. And you cannot be beaten if hearts are 4-4 and you have 3 spade tricks.
No, I meant exactly what I wrote; I believe BBO's claiming algorithm is about as perfect as it can get. It's basically the only aspect of GIB that I find faultless. - smerriman
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#5 User is offline   KingCovert 

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Posted 2020-July-24, 15:29

View Postlamford, on 2020-July-24, 15:05, said:

The only winning line in theory is to cross to a diamond, play a club to the jack and duck a club. You only have three spade tricks, and the opponents should not oblige by cashing the hearts if you play another high club, as South does then get squeezed in the pointed suits. I tried the ten of diamonds en route, but no singleton nine appeared! I made a very poor stab at this, and think your line is best except against world class defenders. And you cannot be beaten if hearts are 4-4 and you have 3 spade tricks.


So, my first thought was to cross in diamond and play clubs from the East. There does seem to be some squeeze potential, by trying to squeeze the majors and convert an extra spade trick or perhaps promote our 10.

I dismissed it for a few reasons.

1) I don't think it's likely that I can successfully duck a club and draw the A, meaning I'm likely creating 2 club losers now and conceding the contract on the spot.
2) I didn't have a clear answer to North holding the A and winning it over our J and promoting the defending team's 3rd round diamond trick. I think there is still squeeze potential here, but,
3) It seems like I'm really forced to play high clubs out of West's hand given #1, and I don't really see a point in creating potential weaknesses in diamonds.

I'm not the strongest with visualizing squeezes though. So, it's entirely possible that this reasoning is rather flawed.
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#6 User is offline   FelicityR 

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Posted 2020-July-25, 03:55

I cannot believe that the probability of finding South with just Ax precisely - North may duck with Ax but doesn't look quite right admittedly - beats my 'kitchen table bridge play' of establishing two winners, guessing the finesse and finding 3-3.

My line looks about 18%. Not sophisticated but practical and we may or may not arrive at nine tricks dependent on how lucky we are.
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#7 User is offline   mikeh 

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Posted 2020-July-25, 07:29

This is an extremely hard problem, but I donít think anyone so far has analyzed it correctly. So hereís my take, which of course may also be wrong😀

Letís assume hearts 4-4, with the added complexity that there are lies where hearts are blocked. Such lies add further complexity because on some of them we have to attack clubs to sever their communication, and that affects our basic analysis.

We have two possible approaches: clubs or spades.

I doubt north would ever duck from Ax. South has to, if we lead through him, but playing low to the dummy and ten low off dummy smacks of desperation. It has to be a very low percentage play, and I know we can do better.

One approach is to combine chances. Win in dummy, cross is diamonds (to cater to south being 4-4-4-1) and play two rounds of top clubs. I reject this, because if we play a diamond early, dummy gets squeezed on the hearts. By playing clubs from dummy at trick 2, we can throw all 3 diamonds on the hearts, preserving all of our black suits.

Watch the club spots! We have 4 club winners by force when an opp holds A109, 109x, or 109 tight. A good defender, especially south from 109xx, can falsecard the 9 or 10 on the second round, so you may need to read your opps.

If no 9 or 10 appears on the first two rounds, you give up on clubs. Unfortunately, the opps will win the second round (or the first, giving you less chance of knowing if clubs come in) and run the hearts

They will then play either a diamond or a club.

If a diamond, you are in your hand and cannot play north for the spade Q. Even Qx does you no good, because if entry issues, so you hav3 to play south for precisely Qxx.

I canít estimate the chances of clubs coming in (especially if they win the first club). And the opps can force you to commit by playing hearts then diamonds, making you pitch a black card from dummy.

South with Qxx in spades is about 18%, maybe a little higher given the assumed heart break and any info we have in clubs (if they duck one club, we eliminate some club lies). Adding in the chances of the 109 of clubs dropping, and fudging for the chance of a falsecard or our giving up on clubs because we have to pitch a black card, Iíd estimate this line at maybe 25%

Is that the best we can do?

We can certainly increase our chances in the spade suit. If south has the Queen, we need him to hold Qxx even if we play on spades right away, although in real life we might get away with Qx once in a while: diamond to the ace, spade to the J, back to the Ace and a club up. A good defender would win the first club.

But if North has Qx or Qxx we have a legitimate line for 4 winners, and preserve an entry to dummy, win the heart, low spade to the 10.

This picks up 3-3 with North holding the Queen, and one sixth of the 4-2 breaks and one twelfth of the 5-1 breaks. Roughly 25%

I think it very close. Of course, Iím estimating percentages here. At the table, against strong opps, I hook spades at trick 2. The club line is too vulnerable to good defence, while the spade line either works or doesnít

Against weak opps, I think Iíd try the club line. Itís more spectacular when it works😀 Iíd be interested if anyone mathematically inclined worked out the percentages (tho one canít work out the odds of anyone falsecard if)
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
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#8 User is offline   lamford 

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Posted 2020-July-25, 16:15

View Postmikeh, on 2020-July-25, 07:29, said:

At the table, against strong opps, I hook spades at trick 2. The club line is too vulnerable to good defence, while the spade line either works or doesn’t

That doesn't work, and my line of running the ten of diamonds at trick two didn't work either. I thought that they might well duck from QJx or QJxx if they could not see the nine. They will cover from QJ9 and I can then think again! In theory, the only winning line is to cross to a high diamond, play a club to the jack and duck a club, but as you say that is not high percentage. I think your line of hooking the spade is probably best, but hearts might be 3-5 with Hxx on lead as well as the blocked positions. I have also found quite a few people aware of "The Telltale Two" not leading the two when they have four but leading it when they have five!
No, I meant exactly what I wrote; I believe BBO's claiming algorithm is about as perfect as it can get. It's basically the only aspect of GIB that I find faultless. - smerriman
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#9 User is offline   mikeh 

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Posted 2020-July-25, 18:20

Frankly, I donít care what works on the actual lie of the cards and donít understand the point of posting a hand, as a problem, and then suggesting, as the correct play, a silly play that happens to work

Learn to make hands that way and one is learning how to be a very bad bridge player or a self-kinitzer😃
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
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#10 User is offline   lamford 

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Posted 2020-July-26, 04:59

View Postmikeh, on 2020-July-25, 18:20, said:

Frankly, I don’t care what works on the actual lie of the cards and don’t understand the point of posting a hand, as a problem, and then suggesting, as the correct play, a silly play that happens to work

Learn to make hands that way and one is learning how to be a very bad bridge player or a self-kinitzer��

I did not suggest that the correct play was to play a club to the king and duck one. I wrote: "I think your line of hooking the spade is probably best". There are three potential plays on the hand. Finessing the spade, playing two high clubs, and running the ten of diamonds.

Frankly, I don't care what your opinion is of what works on the actual lie of the cards, as others might want to know. I don't understand the point of falsely stating that I suggested that the correct play was a silly play that happens to work, and you have gone down in my estimation, as this is the first blemish on your normally excellent posts.

Learn to post responses that way and one is learning to be a very bad poster.
No, I meant exactly what I wrote; I believe BBO's claiming algorithm is about as perfect as it can get. It's basically the only aspect of GIB that I find faultless. - smerriman
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#11 User is offline   nige1 

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Posted 2020-July-30, 11:29


lamford "Div 1 of a National League. South leads the two of hearts (fourth) and North plays the four, which is reverse attitude or reverse count, this exact situation undiscussed. Over to you. Sorry, I left out the auction: 1C-1D-1S-2NT-3NT uncontested."
+++++++++++++++++++++++++

My guess: Win , A. to K, Q, unless T9 or a quack have appeared, finesse T.

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#12 User is offline   lamford 

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Posted 2020-July-30, 17:26

View Postnige1, on 2020-July-30, 11:29, said:

My guess: Win , A. to K, Q, unless T9 or a quack have appeared, finesse T. [/hv]

I think MikeH pointed out that three more rounds of hearts squeeze dummy. I think Mike's line is technically best, of hooking the ten of spades a trick two. If one could be sure that hearts were 4-4 but I note that good playera have taken to leading fifth best when it is the two. The unanswerable question is how often a good player will cover from QJx if you lead the ten, and he cannot see the nine, not to mention the gain when you pin the singleton nine. The technical answer may differ from the practical answer, and the one that actually works is not likely to be found.
No, I meant exactly what I wrote; I believe BBO's claiming algorithm is about as perfect as it can get. It's basically the only aspect of GIB that I find faultless. - smerriman
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#13 User is offline   nige1 

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Posted 2020-July-31, 21:00


My guess: Win , A. to K, Q, unless T9 or a quack have appeared, finesse T.
+++++++++++++++++++++++++++++++
Lamford "I think MikeH pointed out that three more rounds of hearts squeeze dummy. I think Mike's line is technically best, of hooking the ten of spades a trick two."
+++++++++++++++++++++++++++++++
You can discard two s and a but defenders will probably exit in :( The immediate finesse is a good line but risks sudden death. It's human nature to postpone the key decision until defenders have had a chance to go wrong and other slight chances have been discarded :(

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