[kgr]

KQT vs xx
You first play small to the Q, that holds.
Is there any difference in playing small to T or to K next?
(suitplay says play small to K, but I don't see that small to T is any worse. If 2 plays are the same is suitplay only showing one?)

[Jlall]

50/50 technically, just go with psychology.

[Lobowolf]

If your opponents are good, it shouldn't matter. If they're not, play to the other top honor; The opponent behind the Q is more likely to have taken the ace on the first round. If the honor combination is hidden in your hand, play to the king the first time; more likely the ace will be played on the king than the queen. If one of your opponents is good and the other isn't (e.g. pro/client pair), play for the pro to have the queen. He's more likely to have ducked the ace, from either side (and certainly more like to have ducked smoothly).

All of which falls under Justin's suggestion to "go with psychology."

[jdonn]

LHO will pretty much always duck the ace on the first round. But against average or worse competition, I bet I could tell at the table over 80% whether RHO ducked the ace on the first round or LHO ducked the ace on the second round. The better the competition the harder time I have telling, although I still often can.

Other than some sort of count on the hands or other factor about the hand itself, that is what I would go on.

[Jlall]

Lobowolf, on Jul 20 2009, 12:26 PM, said:

If your opponents are good, it shouldn't matter.  If they're not, play to the other top honor; The opponent behind the Q is more likely to have taken the ace on the first round.  If the honor combination is hidden in your hand, play to the king the first time; more likely the ace will be played on the king than the queen.  If one of your opponents is good and the other isn't (e.g. pro/client pair), play for the pro to have the queen.  He's more likely to have ducked the ace, from either side (and certainly more like to have ducked smoothly).

All of which falls under Justin's suggestion to "go with psychology."

It depends. If it's a suit contract and xx is in dummy, almost all RHOs will not duck the second round. You may even elect to play low to the queen first so that when it wins, RHO will KNOW you have KQ so they won't fear crashing their partner's queen or something stupid, and thus be even more likely to win the A on the second round. This applies in situations where they should be ducking anyways since you are just gonna take a useful pitch if you get the trick in this suit. In general agree with all of your points though.

[Trumpace]

In a suit contract, If a good defender sitting over KQT knows that you have xx opposite KQT, maybe it is better to play K on next round.

By ducking the A, the defender over KQT has just given you a free shot at a finesse for two tricks in D, which declarer probably would not take if the Q got captured on the first round.

[kgr]

This is (almost) same as?:
KTx
-
Qx
 
Where you first play small to Q and if the Q holds finesse the T.
For LHO it doesn't really matter to take the Ace if he has had?

[kgr]

And back to:
KQT
vs
xx
 
Suitplay says that if the K looses to the A then play the Q next. This is playing that RHO will only take the Ace with AJ doubleton? Isn't this expecting too much from opps?
And if that is the best play, will RHO not always tkae the A with Ax...?

[kenrexford]

Trumpace, on Jul 20 2009, 01:17 PM, said:

In a suit contract, If a good defender sitting over KQT knows that you have xx opposite KQT, maybe it is better to play K on next round.

By ducking the A, the defender over KQT has just given you a free shot at a finesse for two tricks in D, which declarer probably would not take if the Q got captured on the first round.

Good point. The psychology shifts depending on what else is going on. In the abstract, one play might seem like the "psychological play," whereas in context the reverse might be true.

For that matter, one might be able to manipulate the psychology somewhat by a series of plays or ruses leading up to the guess.

[jdonn]

kgr, on Jul 20 2009, 02:48 PM, said:

This is (almost) same as?:
KTx
-
Qx
 
Where you first play small to Q and if the Q holds finesse the T.
For LHO it doesn't really matter to take the Ace if he has had?

This is different since when you play low to the queen, LHO can guarantee his side two tricks by winning the ace if he has it without the jack. If he ducked then ducked again it would be a grosvenor. So all you are really finessing for is the jack.

[kenrexford]

jdonn, on Jul 20 2009, 03:10 PM, said:

kgr, on Jul 20 2009, 02:48 PM, said:

This is (almost) same as?:
KTx
-
Qx
 
Where you first play small to Q and if the Q holds finesse the T.
For LHO it doesn't really matter to take the Ace if he has had?

This is different since when you play low to the queen, LHO can guarantee his side two tricks by winning the ace if he has it without the jack. If he ducked then ducked again it would be a grosvenor. So all you are really finessing for is the jack.

Well, not technically. Again, the context is important. LHO might duck the Ace because RHO being in first helps the defense, or even is critical.

Or, maybe the Jack is doubleton, and the end position will be such that there is a losing option created by the duck.

[Mbodell]

kgr, on Jul 20 2009, 12:00 PM, said:

And back to:
KQT
vs
xx
 
Suitplay says that if the K looses to the A then play the Q next. This is playing that RHO will only take the Ace with AJ doubleton? Isn't this expecting too much from opps?
And if that is the best play, will RHO not always tkae the A with Ax...?

I think this is the key point. It is much less of an issue with KQT opposite xx than KQTx opposite xxxx or something, but the main point is what would someone do with AJ tight. They'd win the A 100% of the time (absent some side suit issues). Therefore when they win the A on the first round it makes it more likely they have the J, or some such.

There is a BM2000 deal about this (KQT in general) in the B problem sets.

[xcurt]

Mbodell, on Jul 20 2009, 09:57 PM, said:

kgr, on Jul 20 2009, 12:00 PM, said:

And back to:
KQT
vs
xx
 
Suitplay says that if the K looses to the A then play the Q next. This is playing that RHO will only take the Ace with AJ doubleton? Isn't this expecting too much from opps?
And if that is the best play, will RHO not always tkae the A with Ax...?

I think this is the key point. It is much less of an issue with KQT opposite xx than KQTx opposite xxxx or something, but the main point is what would someone do with AJ tight. They'd win the A 100% of the time (absent some side suit issues). Therefore when they win the A on the first round it makes it more likely they have the J, or some such.

There is a BM2000 deal about this (KQT in general) in the B problem sets.

The probability is dominated by what they would do (in practice) with the A and not the J because there are just so many more Ax(x(..)) combinations that the lone AJ tight.

But it is true that the Nash equilibrium, in a vacuum, is what Suit Play is spitting out, by wafer thin margin. AJ tight (a specific 6-2 break) is slightly more likely than stiff A (a specific 7-1 break) by the wide margin of 0.30% to 0.18% and if the defender starts winning the ace from ace-empty, you can switch your play to start finessing and gain more from the ace-empty cases than you lose from the AJ case.