It happens often, that you have to guess, which opponent has a Queen to finesse it. More rarely it happens, that you can play a ruffing finesse or a finesse agains a King. But playing finesse against a King without shortness in both directions possible, that doesn't happen every day. Let's see, what had happened?
I played our year closing big tournament in Hungary with Attila Vikor, my nephew, who is a very talented and sophisticated player. We reached 62,7 %, pretty good result, still we won the bronze medal, congrats for the winners,
We played the following hand in the 2nd round:
Partner's 2♠ response to the 1♥ opening was strong version of Bergen.
Well, I was a bit agressive, and a Splinter 4♣ bid instead 2NT relay, asking for shortness would have been better, but we arrived at a 6♥ contract, and the opening lead was the ten of spades. It must have been short, because we have the nine of spades in out line.
It is a very funny contract. Almost surely working, even if trump is lying 3-0, just you have to find out, which opp has the King of diamonds.
If East has it, you should go with the King of heart to the dummy, if trump is lying 2-1 we should cash another trump and play the finesse in diamonds.
If trump is lying 3-0, and East has 3 hearts, we shouldn't play any more hearts, we should play the finesse in diamond,starting with the low diamond, than we ruff the 3rd round of diamond with a small trump in the dummy, hoping that East has at least three diamonds. If he has only 2 , he will overruff us once, doesn't matter, how do we ruff the 3rd round of diamond in the dummy.
If he has singeton KIng , we should be careful to play low diamond below the Jack, that we shouldn't put the Jack under the singleton King of diamonds, because we will have only 1 trump later to ruff a diamond in the dummy!
If we managed to ruff the 3rd round of diamond with a small trump, we ruff a club in the hand, we ruff the last diamond with the Queen of hearts, and we play a finesse against the Jack of hearts, which is already declared.
If West has 3 trumps and at least 2 diamonds, it is easier, we just ruff 2 diamonds in the dummy, and West cannot do anything against it.
Anyway, we can make the contract even if West has the King of diamonds.
This case we discover the trump lye, after cashing the trumps, we play small diamond from the hand to the Jack, and if West doesn't put the King, we win the trick with the Jack of diamonds and we simply ruff 2 diamonds in the dummy. We have to lose a spade trick later.
If West puts the King of diamond to the 1st diamond trick, we play low from dummy, and later we will have 3 tricks in the diamond suit, and we can discard 2 spades from the dummy, and we win the contract when we ruff our 3rd spade in the dummy.
How should we decide, that which opp has the King of diamonds?
The opening lead can help us this time. West leaded the ten of spades, which play didn't help us in the spade suit, still it was a very dangerous lead from doubleton.
It can be singleton, but than he has a lot of minor cards then, again a point for having the King of diamods too.
Why didn't he lead diamonds? If East has the King, West have had a safety diamond lead, therefore he wouldn't have led the ten of spades.
Therefore it is a much higher probability, the West has the King of diamonds, that that East has it.
So after cashing 2 round of trumps,finishing in the hand, I played a small diamond from my hand, and when West started to think, I could be already sure, that my playline was right.
The complete deal looked like this: