Making the right inference

Lynn Deas, playing with Beth Palmer, made the right inference, and thus found a nice play on this deal from the Women's Team Trials (held in Raleigh NC) in May, 2004:

                ♠ A 3 2
                ♥ 9 8 3
                ♦ A K J
                ♣ A Q 8 6
♠ K J 10 5                      ♠ 9 7 6
♥ 5 2                           ♥ K Q J 7 6
♦ 10 9 6 5                      ♦ 7 3 2
♣ 10 9 2                        ♣ K 7
                ♠ Q 8 4
                ♥ A 10 4
                ♦ Q 8 4
                ♣ J 5 4 3
       North      South
       Palmer     Deas
       1♣         1NT
       3NT        Pass

1♣ was artificial and showed 16+ high-card points.

West avoided leading a spade. That would have given up the ninth trick immediately. Instead she led a low diamond which Deas won in hand to lead the ♣3 to the queen and king.

East shifted to the ♥K, then the ♥Q and another heart as declarer held up until the third round.

At this point, Deas realized that East had a good five-card suit and the ♣ K, yet had not overcalled. Therefore, she decided to play West for the ♠ K.

Deas cashed her tricks in the minors, coming down to only spades in each hand with three tricks to play:

          North
          ♠ A 3 2
West                 East
♠ K J 10            ♠ 9 7 6
          South
          ♠ Q 8 4

Declarer led a low spade from dummy and ducked to West who had only ♠ K J 10 left, and was endplayed.

Notice that if West discards the ♠10 and keeps ♠ K J 5, Deas can still work her magic. When the spade is led from dummy, East must rise with the the 9 to try and prevent the endplay. If East does this, Deas can counter by covering the 9 with her queen. Now the spade return from ♠J 5 will run to Deas' ♠8 for the game-going trick. Bridge is so beautiful.