West leads the 
K, plan your play.
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You wouldn’t think South could manage two heart tricks, but that assumes East-West are infallible. South won the first club and led a heart from dummy, winning with the queen when East ducked and West followed with the deuce. South then drew trumps and led another low heart from dummy. East stewed but put up the ace and led a club. West won; but since South could throw a diamond on the 
K, he lost a heart, a club and one diamond. East’s defense was ill-judged but not a clear error he would have been right if South’s hand had been:
KQJ654 QJ 
54 954
West might have apologized for not playing the jack on the first heart, and could have complimented South for a good deceptive play. Nobody ever became a winner by assuming his opponents were omniscient. Suppose you must play this suit: 
You have nothing to lose by leading the jack. If East plays low, you’ll put up the ace; but you tempt East to cover with Q-10-7. Suppose West leads the J against your notrump contract in this position:
If you fear a shift, take the king and follow with the eight, concealing the three. West may think East has Q-4-3.