Playing teams on BBO last night, I watched an opp give me a gift on a hand that up till that time they had done perfectly on, and all because he got what I consider a simple suit combination wrong.
The eventual declarer held Kxx Ax AQxx T98x and had this auction.
The opening lead was a small spade and partner put this hand down Ax Kxx KJxx AQxx. He won the K of Spades in hand, cashed 3 rounds of Diamonds (they were 3-2) ending on board, cashed the A of Clubs, came to the A of Hearts, and led the 10 of Clubs, LHO playing small (of course!). He had now given himself a problem, what card to play from board. He eventually played small, and lost to the J on his right, LHO later got the K of Clubs for down 1.
After a little thought, he apologized to his partner for not taking the double Club hook as happened at the other table. He did get unlucky to get this Club holding and to get a defender who played low on the K of Clubs smoothly, and the line is not totally unreasonable. Any Club honour shows up early and he has no guess. But these are the kinds of hands where you have to get them, if not right, at least take the highest percentage play.