AJxxx vs Kxx

[mfa1010]

Dummy: ♦K86

 

Declarer: ♦AJ432

 

 

We are in 3NT and need the whole diamond suit to come in. Small to the king and small from dummy. What now? Expert opponents, but maybe not world class.

 

A) LHO plays the ♦T, and RHO ♦5-9?

 

B) LHO plays the ♦7, and RHO ♦5-9?

 

C) LHO plays the ♦7, and RHO ♦5-T?

[whereagles]

I suppose the only reason to play the ace would be that in this particular situation LHO had Q7...

[mfa1010]

I suppose the only reason to play the ace would be that in this particular situation LHO had Q7...

 

Well yes, the reason to play the ace is that LHO might have Qx.

 

My question is a general one unrelated to a given board.

 

Could anything be read from the spot cards?

[dake50]

Plop the HA to see what card LHO plays.

[whereagles]

Could anything be read from the spot cards?

 

Technically, yes and no.

 

No, because the book play is the jack.

 

Yes, because restricted choice applies: 7-T or 7-9 by RHO hints at him having either 7-T/7-9 blank or 7-T-Q/7-9-Q, since with 7-9-T he could always have chosen the "other" card.

[mfa1010]

Technically, yes and no.

 

No, because the book play is the jack.

 

Yes, because restricted choice applies: 7-T or 7-9 by RHO hints at him having either 7-T/7-9 blank or 7-T-Q/7-9-Q, since with 7-9-T he could always have chosen the "other" card.

Right. On the other hand we have been learned that we should always falsecard T from Tx etc to trick declarer into playing for the drop.

 

Maybe then if we don't see the T from LHO it means he doesn't have it?

 

---

 

And what if we have

Kxx

AJ9xx

 

If LHO will often play T from Tx, then it can't be right to play K, low to J when we see only low cards. Either we should go 9 or we should go A.

 

There is a lot more than meets the eye with these combos.

[gnasher]

If it's early in the play, it's often hard for LHO to play the ten from 10x. From his point of view, you may have Q97xx, J97xx, AJ8x, etc.

 

Another consideration is whether they play Smith or frequent suit-preference, and if so what signal you'd expect each player to make.

[mfa1010]

Right. I should have made the long suit dummy.

[gszes]

In the unlikely event that the bidding and previous play of the

hand has given me no clues as to distribution/power I would have

a strong tendency to completely ignore restricted choice in anything

but a beginners game since the spot cards should be randomized by any

remotely competent defender. I would go by the book and take the top dia

in dummy intending to finesse the J.

 

The main reaon for this type of decision is we start off with an

advantage by making the book play and we let the opps try to bust their

brains trying to figure out how to play their 2 small spot cards in a way

that will mess you up:))))))))))))))))))))))))))))))))))))))))))))))))))

 

Top dia in dummy and dia toward J.

 

As an aside, a long time ago a friend of mine decided that they knew when

it was right to drop the Q because of knowing the opps tendencies using

restricted choice. Over the next year they tallied up their results and found

the book play was better (I was shocked I tell you though I could attest to the

number of "bottoms" we received due to this newfound "knowledge". The worst part

of the experiment is that many of these decisions were not made in a vacuum but

even on hands where rho was favored to have the Q sighhhhhhhhhhhhhhhhhhhhhhhhhh.

[Jinksy]

In the unlikely event that the bidding and previous play of the

hand has given me no clues as to distribution/power I would have

a strong tendency to completely ignore restricted choice in anything

but a beginners game since the spot cards should be randomized by any

remotely competent defender.

 

? Restricted choice assumes randomly chosen pip cards. If you think you can read extra info from the opps' non-random play, that's further info.

[Fluffy]

My usual opps only play the 10 from 10x when they are showing doubleton.

[mfa1010]

My usual opps only play the 10 from 10x when they are showing doubleton.

 

Yeah maybe, but I did post in the Expert forum... :)

 

I'm fortunate enough to play in a club game, where just about everyone is fully capable of this false card.

[ArtK78]

Given the weak spot cards present in the OP, the restricted choice implications of the opponent's spot card plays are weak, at best. I would rely on other information available to me from the bidding and play to do anything other than make the normal play of K followed by small to the J. That information would have to be very convincing.

[steve2005]

Given the weak spot cards present in the OP, the restricted choice implications of the opponent's spot card plays are weak, at best. I would rely on other information available to me from the bidding and play to do anything other than make the normal play of K followed by small to the J. That information would have to be very convincing.

 

I agree with Art

[Stephen Tu]

Right. On the other hand we have been learned that we should always falsecard T from Tx etc to trick declarer into playing for the drop.

 

Maybe then if we don't see the T from LHO it means he doesn't have it?

 

If LHO will often play T from Tx, then it can't be right to play K, low to J when we see only low cards. Either we should go 9 or we should go A.

 

It is NOT right to "always falsecard T from Tx". This is the "deep 9" hypothesis advanced by Kaplan in Bridge World many years ago, that good players will falsecard T too often, thus you should deep hook the 9 when the T didn't appear. If you work out the maths, the optimal (i.e. non-exploitable) frequency to falsecard the T is between 1/18 and 3/18. This prevents declarer to gain from picking up qtxx on (because Tx off still frequent enough, you are playing low often enough), or from picking up QT off (because T from Tx is frequent enough).

[dake50]

A priori combination study assumes spots won't tell declarer "new" information.

That's a very common simplifying assumption. With a suggestion that more

CAN be developed atop that a priori.

Go ahead and develop as J.M.Roudinesco's The Dictionary of suit combinations

what each spot sequence may suggest for this combo.

You'll find, as his book has done, that's daunting even to read.

[mfa1010]

Thanks for the posting.

 

Had a discussion lately about the merits of dropping the T behind AJ to induce playing for the drop. In my experience everyone seems to just take their a priori best shot of finessing the jack and not worry to much about all this. That makes the falsecard rather useless in practice.

 

I think there is a definite advantage to be had if ones knows this combination throughoutly, but it is tough. Thanks for the reference to the Roudinesco book.

[mfa1010]

It is NOT right to "always falsecard T from Tx". This is the "deep 9" hypothesis advanced by Kaplan in Bridge World many years ago, that good players will falsecard T too often, thus you should deep hook the 9 when the T didn't appear. If you work out the maths, the optimal (i.e. non-exploitable) frequency to falsecard the T is between 1/18 and 3/18. This prevents declarer to gain from picking up qtxx on (because Tx off still frequent enough, you are playing low often enough), or from picking up QT off (because T from Tx is frequent enough).

 

It was stuff like this I was looking for. Thanks.