We don't often feature an undoubled part-score deal in this space, but today's deal illustrates an important defensive principle. The hand was played in the USA Team Trials in 1998, so all the players were experts. It is always good fun to show a deal where an expert got it wrong.
South played low from dummy on the opening spade lead and East used the "Rule of Eleven" when deciding what to play. The rule told East that declarer held only one card higher than the seven. Should that card be the 10, it would be better for East to play the queen, but should that card be the ace, king or eight, the nine would be the winning play. Accordingly, East made the expert play of the nine at trick one. Good start!
East continued with the queen of spades and here came the problem. West carelessly followed suit with the three of spades. It couldn't possibly matter to East how many spades West had originally. The only thing East wanted to know was which suit to play next. Where was West's entry? The hearts in dummy reduced the decision to a choice between diamonds and clubs. East, who knew that West held the 10 of spades, interpreted the low spade from partner as a request for the lower ranking of the two remaining suits. East shifted to a club, and declarer took nine tricks instead of the defense taking eight.
Had West played the 10 of spades at trick two, this hand would have been long forgotten.