You are South here. At a club game, partner judges well to bid to 3H over their 3D:
You get the lead of a King diamond and then opponent switches to a low heart. You play low from dummy and East inserts the Jack of hearts. Opponents are not experts -- they do not play Rusinow or anything. How do you play? (The bidding shown is slightly wrong. It is East who bid 3D over 2H)
I read the diamond situation as Ace of diamonds to my right. I took the heart with the Ace and gave up on getting two diamond ruffs (so would have only one loser anyway). Instead, I finessed the 10 of hearts and played the King to pull the last trump.
I then played a club to my Ace and a low club. What should you play from dummy?
West has already shown up with 5 points (heart queen, diamond king) and probably has one spade honor to get to 8 points. She also must have no more than 3 spades since with 4, she'd probably have doubled (negative). That means West's distribution ought to be 2-3-4-4 or 3-3-4-3. If East has a guarded queen, I have no hope of making the contract, and so I need to play the King for the drop.
It was still a top board for us because everyone else was in 3D making. Still, I should learn to infer a count of all four suits and high-card points. This sort of half-assed play will not do.
p.s. You can click on "Next" above to see how the play should have gone after the helpful lead.