[steve2005]

Trump is
A976543
QT
There are no entries to dummy so have to lead from long suit.
Opponents have KJ82 between them.

[smerriman]

My non-expert thoughts:

Leading the A can't be right (unless you're worried about ruffs elsewhere). Not sure what 'know next' means; at that point you have a singleton so it doesn't matter what you know..

The only time the other two options make a difference is if the 2nd hand to play holds Kxx or Jxx - they may go up with the K on some occasions, so I'd play the Q T (fixed typo, thanks).

[sfi]

smerriman, on 2017-November-09, 21:55, said:

The only time the other two options make a difference is if the 2nd hand to play holds Kxx or Jxx - they may go up with the K on some occasions, so I'd play the Q.

This line of logic would suggest playing the 10 rather than the queen (which is what I suspect you meant). It's a pretty weak inference, but there is no technical difference between the two so you might as well use that.

If you had entries to dummy, the best line is to play the queen intending to finesse and cash the ace next round. All sensible lines of play (lead queen, lead 10, low to queen and low to 10) give you the same chance of 6 tricks, but leading the queen is the only one with any play for 7 tricks.

[steve2005]

smerriman, on 2017-November-09, 21:55, said:

My non-expert thoughts:

Leading the A can't be right (unless you're worried about ruffs elsewhere). Not sure what 'know next' means; at that point you have a singleton so it doesn't matter what you know..

The only time the other two options make a difference is if the 2nd hand to play holds Kxx or Jxx - they may go up with the K on some occasions, so I'd play the Q T (fixed typo, thanks).

ruffs are not a worry. though possible there is nothing on bidding to suggest opps have shortness.
yes your right if play ace then you play your other trump in dummy

unfortunately no way to dummy to lead Q.

[Cyberyeti]

Possible holdings for the hand over the long suit

KJ82 (leading A loses, others the same)
KJ8 (leading A loses, others the same)
KJ2 (leading A loses, others the same)
K82 (small to 10 loses, others win)
J82 (small to Q loses others win)
KJ (same)
K8 (same)
K2 (same)
J8 (same)
J2 (same)
82 (same)
K (same)
J (same)
8 (same)
2 (same)
void (leading A loses others the same)

So in abstract small to Q or small to 10 are equivalent and better than A.

In practice Kxx may play K, Jxx won't play J so this favours the 10.

[Tramticket]

steve2005, on 2017-November-09, 20:35, said:

Trump is
A976543
QT
There are no entries to dummy so have to lead from long suit.
Opponents have KJ82 between them.

The diagram confused me at first. I took the long suit to be dummy.

Once I got orientated,I agree with others that low to ten is best.

[miamijd]

Cyberyeti, on 2017-November-10, 07:13, said:

Possible holdings for the hand over the long suit

KJ82 (leading A loses, others the same)
KJ8 (leading A loses, others the same)
KJ2 (leading A loses, others the same)
K82 (small to 10 loses, others win)
J82 (small to Q loses others win)
KJ (same)
K8 (same)
K2 (same)
J8 (same)
J2 (same)
82 (same)
K (same)
J (same)
8 (same)
2 (same)
void (leading A loses others the same)

So in abstract small to Q or small to 10 are equivalent and better than A.

In practice Kxx may play K, Jxx won't play J so this favours the 10.

+1

[heart76]

I'll also try with my non-expert answer
Playing against 2-2 (36%?) you always have just 1 loser.
Playing against 3-1 (42%?):
- Kxx onside would play low, hoping J is with partner
- Jxx onside would play low
- what would KJx play? I guess K to switch to a short suit.

So it seems right to me to play small to the Q, if the K doesn't show up. If the K wins, I pull the A at the next round.
This loses only against KJx behind. Right?

If you had side communication, playing the Q for the finesse would work only against Kxx-J. Would it be better than playing anyway small towards the Q?
If your side communication is needed for something else, even a potential squeeze, I guess I would still lead low to the Q.

[sfi]

heart76, on 2017-November-14, 03:43, said:

- what would KJx play? I guess K to switch to a short suit.

What would KJx play? That would depend on the rest of the hand. However, it doesn't matter whether you play the T or the Q if they play small. Either way you only have one loser.

Quote

So it seems right to me to play small to the Q, if the K doesn't show up. If the K wins, I pull the A at the next round.
This loses only against KJx behind. Right?

Not quite. It also loses to singleton king on your right.

Quote

If you had side communication, playing the Q for the finesse would work only against Kxx-J. Would it be better than playing anyway small towards the Q?
If your side communication is needed for something else, even a potential squeeze, I guess I would still lead low to the Q.

Playing the queen for the finesse only gets seven tricks when there is Kxx-J, which is why it is better. It gets six tricks on KJx-x, J-Kxx and K-Jxx (4 3-1 breaks), and the other sensible lines pick up 5 of the 3-1 breaks as well - just not the same 5 every time.

[gszes]

+ 1 for cyberyeti. He displays the concept of imagining losers to help determine the overall best choice. I only add that ALWAYS take into account any other clues provided via the bidding that might provide insight as to the best choice (between low to the T or low to the Q). The bidding goes 1n (15-17) p p 2s (by you) and that ends the bidding. In this case the auction strongly suggests leading small to the Q is superior unless there are other clues provided in the play of the hand that suggest otherwise. Say lho leads AK AK and switches to the J of the 3rd suit. LHO can no longer mathematically hold the trump K (thank them for being so helpful in your head not out loud) so we should either bang down the trump A or play cute and lead low to the T (merely to show off) expecting both plays to end up with the same result while playing low to the Q now becomes dramatically inferior (though it could still work)