There are days on defense when you are dealt the right cards. Your partner makes a good lead, and you have an eight or a nine with which to encourage him to continue. On bad days, you have only the two and the three with which to signal. He thinks your three is discouraging and makes a fatal shift.
This deal occurred during an expert knockout team match. At the first table, North was the declarer in four spades undoubled. East led his singleton club. Declarer won with his ace, drew trumps in three rounds and ran the clubs, discarding two heart losers. Then North led a diamond and lost only three red-suit tricks.
At the other table, the bidding, which is given in the diagram, was aggressive. South, with such a balanced hand, might have doubled four hearts and collected 200 or 500. Instead, he went for his own game.
West led the diamond ace. East was in an ideal position: He dropped the diamond nine. Whether his partner thought this was encouraging or a suit-preference signal for hearts, East held what was needed! West, holding a singleton diamond, read the signal as suit preference and switched to a low heart at trick two. East won with the heart queen, cashed the diamond king, gave his partner a diamond ruff and regained the lead with the heart king. Now a fourth diamond effected a trump promotion. If South had ruffed low, West would have overruffed, but when declarer ruffed high, East scored a trick with his spade jack. Down three, plus 500, and a gain of 14 international match points.