If diamonds are 3-3, you cannot make the hand. You cannot squeeze him out of holding 3 diamonds and a heart and you have set up a heart trick for him, needlessly if you overtook the K with the A. You'll know (assume) how many diamonds lho holds after running three spade tricks. And I think I should have cashed dummy's heart at trick one and my heart at trick two so I would know exactly how many hearts he has. I assumed he had 8 or 9 hearts, giving him 8 if rho followed, but that is a bit sloppy. Given that he has 8 or 9 hearts (and you can eliminate 9 at trick 1 if rho follows) and if he has zero clubs, like we believe he has, you will know how many spades he holds by the 3rd round of that suit. And you will assume an exact count on the hand. If he has no spades, you are going down because you have a spade loser. If he follows only to 1 spade, he will have 4 diamonds and you can only pick the suit up if rho has the doubleton 9, and only then if you have unblocked the suit to hold the lead in your hand so you can repeat the finesse unless he covers. If he follows to 2 spades, he will have three diamonds and you are right that you don't need to unblock but you will go set because you will be locked in dummy after the first finesse and unblocking will not work because he can then cover the 10, setting up his partner's 9xx for the setting trick. You cannot squeeze him in hearts and diamonds because he can pitch all his hearts and when you cash your little heart in your hand, if it is good, you pitch dummy's small diamond, dummy's last three cards would be the diamond AQJ and a finesse could not pick him up because you will be locked in dummy, unable to repeat it, unless you have unblocked the suit. And if you unblocked with 3-3 diamonds, lho can cover the 10 with K9x and you lose to the 9 or he will cover the 10 if rho has the 9 and that will set up.
