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First among Equals Duck or Grouse?

#1 User is offline   lamford 

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Posted 2015-September-08, 02:46


Playing EHAA with an occasional partner, I ambitiously drove to slam on the South hand above. West led the ten of diamonds and East played the four, normal attitude. I cashed the ace of spades, eight, four, jack. The opponents are playing normal count. I now continued with the the three of spades and West played the nine. Which card should I play from dummy?
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#2 User is offline   wank 

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Posted 2015-September-08, 03:45

i play the queen....er no i don't, see below.

more people play high from touching cards than low in my experience.

on thinking about it more, is west forced to play the 9 from 1098 on the second rough to protect east's king? if he plays the 10, he exposes the jack as a true card from kj, because east probably wouldn't drop jack from j9, lest declarer has atx. similarly, west's choice on the first round is limited by not wanting to create a similar situation. so we can discount any PRC effects from west and just go on east's play and try to drop the king.
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#3 User is offline   zasanya 

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Posted 2015-September-08, 03:52

View Postlamford, on 2015-September-08, 02:46, said:


Playing EHAA with an occasional partner, I ambitiously drove to slam on the South hand above. West led the ten of diamonds and East played the four, normal attitude. I cashed the ace of spades, eight, four, jack. The opponents are playing normal count. I now continue with the the three of spades and West plays the nine. Which card should I play from dummy?

The missing cards are KJ1098. Both of them are showing odd number of cards . One of them doesn't have . Who? What can W have? KJ9 or K109 or J109 K9 or j9 109 or 98 9 singleton . We discount 109 and J9 89 and the singleton 9. If W has J109 he might have played any one of them .So I give him the King and play the Queen. Looking forward to your answer.
Aniruddha
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#4 User is offline   mgoetze 

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Posted 2015-September-08, 03:59

You can never win if East started with KJT, so disregard that. If he started with KJ he will likely always play the J, but if he started with JT he should randomize. However, even half the chance of JT is enough to beat the chance of KJ when combined with the full chance of East having started with the singleton J, thus play the Q. Should win about 57% of the time.

I suppose I could think about whether West, from an original holding of T98, profits from nonrandomly playing the 9 rather than the T to make us go astray, but I'll leave that to someone else.
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#5 User is offline   StevenG 

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Posted 2015-September-08, 04:39

Deleted - rubbish
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#6 User is offline   mgoetze 

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Posted 2015-September-08, 05:07

View PostStevenG, on 2015-September-08, 04:39, said:

The case when East starts with singleton Jack doesn't matter. West has KT98 and you're off regardless.

I must be missing something, could you explain?
"One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision"
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#7 User is offline   lamford 

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Posted 2015-September-08, 05:10

There are some interesting questions here. With Jx, should East give count, to stop his partner rising on the second round with KTx (as his partner does not know whether South has two or three spades), or should he play low in case South has ATx, or should he play randomly? With KT98 should West always rise on the second round, in case his partner has Jx when declarer will always play the queen? There could well be a loser outside spades from both defenders' points of view. Indeed, as mgoetze points out, rising will work in this last case.

Let us surmise that there are only two possibilities for a moment. T98 opposite KJ and K98 opposite JT. If East has JT, he should always play the jack, as that will allow his partner to duck on the second round safely from K98. With KJ, he should always play the jack, as the king is ridiculous. So there is no restricted choice there. Let us look at West. If he has K98, he does not need to give count on the first round, as his partner has no decision, so he can play the nine or eight in either order. He therefore has two ways to play this combination. With T98 he must start by giving true count, as the last thing we want is partner ducking with Kxx when declarer has AJ doubleton. However on the next round he has a free choice. However, he has three ways to give true count, 9T, 8T and 89. So the chance of him having T98 is reduced by more than the chance of him having K98. Therefore I think declarer should play the queen on the second round.

But I might be talking complete bollocks!
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#8 User is offline   nige1 

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Posted 2015-September-08, 06:45


Lambert asks "Playing EHAA with an occasional partner, I ambitiously drove to slam on the South hand above. West led the ten of diamonds and East played the four, normal attitude. I cashed the ace of spades, eight, four, jack. The opponents are playing normal count. I now continue with the the three of spades and West plays the nine. Which card should I play from dummy?"

View Postlamford, on 2015-September-08, 05:10, said:

Let us surmise that there are only two possibilities for a moment. T98 opposite KJ and K98 opposite JT. If East has JT, he should always play the jack, as that will allow his partner to duck on the second round safely from K98. With KJ, he should always play the jack, as the king is ridiculous. So there is no restricted choice there. Let us look at West. If he has K98, he does not need to give count on the first round, as his partner has no decision, so he can play the nine or eight in either order. He therefore has two ways to play this combination. With T98 he must start by giving true count, as the last thing we want is partner ducking with Kxx when declarer has AJ doubleton. However on the next round he has a free choice. However, he has three ways to give true count, 9T, 8T and 89. So the chance of him having T98 is reduced by more than the chance of him having K98. Therefore I think declarer should play the queen on the second round.
Like mgoetze and Lamford, I guess to play Q
  • Ducking wins when RHO has KJ
  • Playing the Q wins when RHO has singleton J or doubleton JT. (RHO can randomize his play from JT but it's dangerous to play J from Jx -- in case declarer has T -- you don't want to signal with a potential trick).
  • LHO should show odd-length but might be wary of playing 8T or 9T because that eliminates the possibility of RHO having JT .

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#9 User is offline   phil_20686 

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Posted 2015-September-08, 07:36

Against good but normal opponents east will play the J from KJ J or JT only. Playing from J9 on the first round will seem ludicrous if declarer next produces the ten from hand from ATx. A play in which then partner is then forced to give access to the winning spades in dummy or afterwards to be thrown in with it later.

Playing the Q wins against 2/3 of the holdings which matter.

Phil
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#10 User is offline   lamford 

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Posted 2015-September-08, 09:20

View Postphil_20686, on 2015-September-08, 07:36, said:

Against good but normal opponents east will play the J from KJ J or JT only. Playing from J9 on the first round will seem ludicrous if declarer next produces the ten from hand from ATx. A play in which then partner is then forced to give access to the winning spades in dummy or afterwards to be thrown in with it later.

Playing the Q wins against 2/3 of the holdings which matter.

Phil

The jack cannot be a singleton. West, unless a complete retard, would win the king from KT98 on the second round, as declarer may have only two spades. Assuming "normal" opponents who can add up to thirteen. And this answers nige1 too on the question of the singleton jack.

East cannot have J9 either, as you have seen the nine. The only holdings he can have are KJ or JT. We are therefore comparing the following:

a) West started with T98 and played 8,9. East started with KJ and played J, perforce,

b) West started with K98 and played 8,9. East started with JT and played J.

They are close. With K98, West can play the 8 or 9 randomly without fear. With T98, he will probably not want to play the ten on either of the first two rounds, as that will make his partner's jack look like it came from KJ doubleton, and he will always want to give true count. Maybe ducking is the right play after all.
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#11 User is offline   nige1 

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Posted 2015-September-08, 09:34

View Postlamford, on 2015-September-08, 09:20, said:

The jack cannot be a singleton. West, unless a complete retard, would win the king from KT98 on the second round. Assuming "normal" opponents who can add up to thirteen.
Please take that past me slowly :)
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#12 User is offline   phil_20686 

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Posted 2015-September-08, 09:40

View Postlamford, on 2015-September-08, 09:20, said:

The jack cannot be a singleton. West, unless a complete retard, would win the king from KT98 on the second round. Assuming "normal" opponents who can add up to thirteen. And this answers nige1 too on the question of the singleton jack.


Its not clear that that is the case at all. If he has that holding he will know for sure that declarer has 3 and his partner has singleton J, in which case what does he have to lose by ducking, unless his partner has an ace. But he knows for sure from the bidding that south has all the remaining key cards, since they apparently bid keycard so rising would be a poor play, ruining your chance to go wrong in the spade suit.
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#13 User is offline   lamford 

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Posted 2015-September-08, 10:02

View Postphil_20686, on 2015-September-08, 09:40, said:

Its not clear that that is the case at all. If he has that holding he will know for sure that declarer has 3 and his partner has singleton J, in which case what does he have to lose by ducking, unless his partner has an ace. But he knows for sure from the bidding that south has all the remaining key cards, since they apparently bid keycard so rising would be a poor play, ruining your chance to go wrong in the spade suit.

If West started with KT98 he will not know that declarer has three spades. It is just as likely that his partner has Jx and declarer has Ax, when rising guarantees that declare only makes one spade trick. Also, he should have played the ten on the first round with that holding, so that his partner knows that he can afford to play the jack from Jx.

If South's two of spades were the five of clubs, he would have played exactly this way, and how would ducking with KT98 look now?
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#14 User is offline   gszes 

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Posted 2015-September-08, 10:10

IHMO this is a bad time to apply restricted choice. There is no reason rho can assume lho does not need spade count since they may need to know when to take their (presumed) spade K. rho does not know we have 11 top tricks and we might very well need the spade suit so rho must make sure lho ducks the 2nd round of spades by giving accurate count with the JT. Does that mean this is a toss up? We know we need lho to hold 3 spades and rho to hold 2 spades thus making lho a 3/2 favorite to hold the spade K.

Rise with the Q

The fact that this agrees with restricted choice is a happy coincidence:)
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#15 User is offline   lamford 

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Posted 2015-September-08, 10:19

View Postgszes, on 2015-September-08, 10:10, said:

We know we need lho to hold 3 spades and rho to hold 2 spades thus making lho a 3/2 favorite to hold the spade K.

We already are pretty sure that LHO has 3 spades and RHO 2 spades, but West is now only 50% to hold the spade king, unless you consider PRC. The reason is that you have already seen two spades from West and one from East, so there is one each remaining, and neither opponent would have played the king unless forced to do so.

How would you play if East had played the ten on the first round of spades, and every other detail of the play was identical?
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#16 User is offline   nige1 

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Posted 2015-September-08, 10:23

View Postlamford, on 2015-September-08, 10:02, said:

If West started with KT98 he will not know that declarer has three spades. It is just as likely that his partner has Jx and declarer has Ax, when rising guarantees that declare only makes one spade trick. Also, he should have played the ten on the first round with that holding, so that his partner knows that he can afford to play the jack from Jx. If South's two of spades were the five of clubs, he would have played exactly this way, and how would ducking with KT98 look now?

With Lamford's hypothetical hand, declarer might cash AKQJ AKQ AKQ.


Now, if x isn't good, declarer would still retain the options of
- Attempting to endplay a defender who holds a winner and Kx
- Leading A and another in the hope that LHO is down to tripleton Kxx

Edited to restore 13th card to North, as suggested by Lamford

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#17 User is offline   lamford 

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Posted 2015-September-08, 10:33

View Postnige1, on 2015-September-08, 10:23, said:


With Lamford's hypothetical hand, declarer might cash AKQJ AKQ AKQ.


Now, if 2 isn't good, declarer would still retain the options of
- Attempting to endplay a defender who holds a winner and Kx
- Leading A and another in the hope that LHO is down to tripleton Kxx


I have restored a thirteenth club to the North hand. Declarer might play as you suggest, but that will give opponents a chance to give count. Playing spades immediately has its appeal as well, especially if West will duck from KT98, as I am definitely going to rise this time.

And there a host of hands where declarer has a likely loser outside spades, where the defender with KT98 has to win the second spade. For example, South might have Ax AKQ AKQJ AKJT
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#18 User is offline   phil_20686 

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Posted 2015-September-08, 10:43

View Postlamford, on 2015-September-08, 10:02, said:

If West started with KT98 he will not know that declarer has three spades. It is just as likely that his partner has Jx and declarer has Ax, when rising guarantees that declare only makes one spade trick. Also, he should have played the ten on the first round with that holding, so that his partner knows that he can afford to play the jack from Jx.

If South's two of spades were the five of clubs, he would have played exactly this way, and how would ducking with KT98 look now?


You are dreaming Paul. RHO will never discard the J from Jx if I play the 8 from KT98. From easts point of view Declarer could at trick one have had AT9 and be about to guess the spade suit wrongly!!!! If I play the ten then he probably will play the J from Jx.

Also, if he does have Ax he might have played a low spade up first. Against lots of holdings playing the ace just guarantees that the opponents will duck the optimal number of times. E.g. if you had Ax and lho has KJTx opposite 98, then the defence cannot go wrong if you play ace of spades and a spade. He just wins the Ks soon as he sees the 9 from partner.

Finally, you cannot seriously be arguing both that its right to duck here and that its trivial for lho to win the K from KT98 on the second round. If its right to duck the Q then it can hardly be trivial to play the K from KT98, since ducking would set the contract on layouts like this!
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#19 User is offline   lamford 

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Posted 2015-September-08, 10:44

View Postphil_20686, on 2015-September-08, 10:43, said:

You are dreaming Paul. RHO will never discard the J from Jx if I play the 8 from KT98. From easts point of view Declarer could at trick one have had AT9 and be about to guess the spade suit wrongly!!!! If I play the ten then he probably will play the J from Jx.

That is exactly the point I made.
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#20 User is offline   phil_20686 

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Posted 2015-September-08, 10:49

View Postlamford, on 2015-September-08, 10:44, said:

That is exactly the point I made.


Sorry didnt read it properly. But I still think that it doesn't follow from this that he can't have KT98, he might just have decided that on this auction against this pair he will play to disguise the spade solution, trusting south to have been expecting this dummy. Or he might just have played badly on the first trick. It happens quite a lot!
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