Here was the original problem:
Deal four — 3♠️ South
Solution–
At this suit contract partner will not have lead away from the A♥️. You should put in the 10♥️ and save your K♥️ to capture Dummy’s Q♥️. This could be the layout:
Playing the 10♥️ on trick one holds declarer to one ♥️ trick. If you play K♥️ on trick one then declarer gets an undeserved second ♥️ trick. Even if Declarer has the J♥️ and the A♥️, playing the K♥️ will give away a ♥️ trick. This is a common theme when Dummy has an honor and third hand has a higher honor.
