[se12sam]

I need some guidance. While declaring, what is your thought process on potential deceptive plays by defender? Do you (as a rule) pay-off a deception (i.e. assume normal play)?
Let me elaborate with a constructed (and possibly primitive) example below:

Scoring: XIMP

You reach 4♥ as South. West leads ♦Q. You win in dummy and play top 3 spades (ruffing in dummy).
You lead ♥5 to the ♥7, your J and West's ♥A. In tempo, west plays a high diamond and you are in dummy for the final time.
Do you play a low club off dummy? Or do you continue with a low trump (hoping to finesse East's ♥Q?
Assume that opponent carding is not helpful and that opponents are expert. What would you play from dummy at trick 7?

---

If East / West are expert, there is still a decent chance that West has the ♥Q (even a ♥AQ doubleton is not ruled out). There are frequent such situations that arise in normal play
- A finesse wins, but when you repeat it you find it loses
- Holding KQTx (in hand) opposite xxx, you play low to the King winning. Next time, low to Queen and West produces the Ace.
Sometimes I realise such positions as declarer. And I find myself spending energy/time thinking whether opponents were being deceptive. My key question is -- Am I fretting about something that should not bother me? Should I pay-off a deception? Thanks

[Hanoi5]

I think you have to 'measure' your opponents expertise, are they good enough to come up with such a play? Maybe the mistake comes up from you, you could have started with the club expasse instead of the trump finesse (though it could have led to a similar problem, HOWEVER, opponents didn't know yet that you held ♠AK...).

So try to 'know' people and decide on that.

[Apollo81]

Strictly speaking, you should play a club to the King on trick 2 on this hand. This allows you to reenter dummy twice later, thus allowing all finesses to be attempted.

To answer what you really asked though, there are not that many true experts (people who are good enough to always play the ♥A in tempo when also holding the ♥Q and no ♣A) around compared to advanced or near-expert players. Against a true expert, you truly have a guess, assuming the auction gives no clues. Against most people, take the marked heart finesse.

[gnasher]

LHO would have to be very good and be looking very alert for me to consider playing a club here. For him to have won the ace from AQ, he has to:
- Be good enough to do it
- Be awake
- Be quick enough to have worked it out in advance.
Ordinarily good players just don't manage all three of those often enough to justify playing for it.

[CSGibson]

I would always take the heart hook again (though I played to the club K the first time before taking 3 rounds of spades). There's some element of risk in LHO ducking from AQ tight (he doesn't know you have exactly 6 hearts, I'm assuming), so even a top notch expert might not find the play. If they do, you tip your hat to them.

[gwnn]

I'm simplifying things here but basically the ♣A is 50% to be onside but the ♥Q is at least 90%, even against very good opps.

[FrancesHinden]

The example hand you give is not really in the same category as the other hands you write about.

There are (at least) three different types of play you mention:

i) A necessary duck
ii) A mandatory false card
iii) Playing an 'unnecessary' false card

Winning with the Ace rather than the queen in the position you give is the last of these. This type of play is generally very rare, and usually you should just pay off to it. (Although as others have pointed out your example hand is flawed, because you originally had time to take all the finesses.)

There are various 'mandatory' false cards (such as the Q from Q10 doubleton sitting over J9xx with AKxx in hand) which against any even vaguely decent player you should always consider, but their very nature means that you will usually pay out to them.

Another good example is playing the 9 from J9xx when declarer's trumps are KQ8x opposite A10xx and you are under the Ace. You will usually play for the 9 to be a singleton because that's more likely than that they found the false card. However, as declarer, you should stop and think about who is likely to have four trumps and play accordingly, don't just 'believe' that the 9 must be a singleton. You should also start the suit from the KQ8x hand if possible, because the false card looks very silly if the singleton is the 10, for example - don't give the putative J9xx hand a chance to see partner's singleton first.

The first of these - a ducking play - is typified by KQ10x in dummy opposite xxx in hand. It's not really a deceptive play rather a mandatory play. If they take the ace from Ax or Axx then you will get the suit right next round. If they duck the ace then you have a guess next round. Similarly if you have AQJxxx opposite 10x and no outside entry, you can expect the 10 to hold the trick on the first round no matter who has the king.

[andy_h]

I don't think we have time to take all the finesses, well, tricks that is. Say we played a club on the 2nd trick and RHO rises with the Ace. RHO may then switch to a trump and if they're 3-1 with AQx offside, we won't be able to ruff a spade.

[Free]

A ♣ from dummy at trick 2 is probably better (only 1 potential danger: if RHO has the Ace, he can take it and play ♥ through our suit which causes us to go down if W has ♥AQx).

Now I think you better finesse again in most situations.

[gnasher]

The layouts where the two lines risk the contract are almost the same.

Comparing (1) spade ruff, heart, planning to repeat the heart finesse if it works, and (2) a club at trick two :

(1) gains when hearts are AQx-x and ♣A is onside and RHO is going to win ♣A to play a trump.
(2) gains when hearts are AQx-x and ♣A is onside and LHO is going to win ♥A.
(2) also gains when hearts are AQ-xx and ♣A is onside and LHO is going to win ♥A.

How often will RHO find the right defence with ♣A and a singleton trump? Not often, I'd guess, but it does depend on the auction.

This post has been edited by gnasher: 2009-June-27, 06:49

[barryallen]

Really bad example. This is one of those cases where you can have your cake and eat it. The problem is that you have created a situation where that is no longer the case.

[se12sam]

barryallen, on Jun 27 2009, 02:16 PM, said:

Really bad example. This is one of those cases where you can have your cake and eat it. The problem is that you have created a situation where that is no longer the case.

How about this one then? Is this a better example or a worse one?
http://webutil.bridg...etch.php?id=144

[barryallen]

se12sam, on Jun 27 2009, 08:41 AM, said:

barryallen, on Jun 27 2009, 02:16 PM, said:

Really bad example. This is one of those cases where you can have your cake and eat it. The problem is that you have created a situation where that is no longer the case.

How about this one then? Is this a better example or a worse one?
http://webutil.bridg...etch.php?id=144

You cannot argue with good play, but you still have to play the percentages otherwise you end up giving away points where it was not necessary. I believe the biggest problem is that when positions are considered nailed on, rather than reflecting upon from that point onwards what an acceptable outcome would be. In a lot of hands it can be avoided by the line initially taken, but if you do fall to such a ruse you can only congratulate the opposition if you have done all you can. If you notice with all the good players they are very aware and even more so, have an excellent nose for sniffing these out. Very similar to the top poker players in a lot of respects. Can that be taught? only sure thing is being aware of the possibilities and letting what ever talent you have in that area come through.

Going back to the example on bridgebase, what have you lost / gained by taking the ♥ finesse first? The odds are still 50/50 for success of either finesse and if that loses you still have the option of the trump finesse with the possibility of being able to smother the trump J when it is a doubleton or leading small to a bare AK?

[gnasher]

se12sam, on Jun 27 2009, 02:41 PM, said:

How about this one then? Is this a better example or a worse one?
http://webutil.bridg...etch.php?id=144

I find it easier to win the king from AKJ than the ace from AQx, and much easier than winning the ace from AQ only.

As declarer against good opposition, you might reasonably assume that from AKJ they'll always win with a high one (unless they have ♥Qx, of course). Even against a world-class player, we can forget the idea that they might have falsecarded with AJ or KJ only.

In that case:
- A heart finesse gains against ♥Qxx(+) onside with ♠AKJ offside
- A second spade finesse gains against ♥Q offside and ♠HJx or ♠Jxx onside.
(I've assumed that if you take an unsuccessful heart finesse you will then try to pin ♠J.)

That makes the second spade finesse correct, regardless of how good LHO is.

So no, it's not a good example of the point you were making, but it's an interesting hand.

[MFA]

How often have you been taken in by some really deep deceptive play? I think that the answer to this will also answer your initial question. Let them shine if they find some very nice play.

[se12sam]

gnasher, on Jun 27 2009, 07:09 PM, said:

se12sam, on Jun 27 2009, 02:41 PM, said:

How about this one then? Is this a better example or a worse one?
http://webutil.bridg...etch.php?id=144

I find it easier to win the king from AKJ than the ace from AQx, and much easier than winning the ace from AQ only.

As declarer against good opposition, you might reasonably assume that from AKJ they'll always win with a high one (unless they have ♥Qx, of course). Even against a world-class player, we can forget the idea that they might have falsecarded with AJ or KJ only.

In that case:
- A heart finesse gains against ♥Qxx(+) onside with ♠AKJ offside
- A second spade finesse gains against ♥Q offside and ♠HJx or ♠Jxx onside.
(I've assumed that if you take an unsuccessful heart finesse you will then try to pin ♠J.)

That makes the second spade finesse correct, regardless of how good LHO is.

So no, it's not a good example of the point you were making, but it's an interesting hand.

We haven't considered spades to be genuinely 1-4 with West having a singleton Ace or King. If we exclude all 5-0 splits after the first round of spades, a 1-4 split (East longer) should be approx 15% chance. However, a heart queen is still only slightly lower than 50% (if spades are 1-4, west has more "vacant spaces")

[gnasher]

se12sam, on Jun 28 2009, 10:11 AM, said:

We haven't considered spades to be genuinely 1-4 with West having a singleton Ace or King.

True, but I don't think it's enough to change the right line. The heart finesse gains against two 4-1 breaks and one 3-2 break, and only if ♥Q isn't doubleton. A second spade finesse gains against five 3-2 breaks.

(I've treated the ace and king as being indistinguishable. If you prefer to think in Restricted Choice terms, divide all the above numbers by two.)