Matchpoint pairs.
West plays in 4H after the opponents have bid and raised spades.
The defence start with 2 rounds of spades (South wins the jack and returns a low one) and declarer ruffs.
Declarer draws trumps in 4 rounds, his LHO having 4.
Declarer plays the ♣K and his LHO takes the ace and plays ♠K, ruffed with the last trump.
Declarer now play a diamond to the 9, king and ace.
RHO cashes ♠A on which declarer discards a diamond and next hand follows suit. Declarer now claims for two off (not stating a line) expecting the fifth spade next with the 2 minor suit queens taking the last two tricks.
What declarer did not notice is that his RHO had discarded a spade when declarer was in the process of drawings trumps. The defender admits to this and says hes going to play a low diamond. The TD is called (by dummy) and this is the 3-card minor suit ending:
TD's ruling: one trick to declarer, two to the defence.
Basis of TD's ruling: finessing ♦10 is a normal line of play, so declarer only makes ♣Q.
E/W appeal.
Basis of appeal: declarer claimed two tricks which were the minor suit queens, known to be winners. The defence cannot prevent him from winning these tricks. In practice ♦10 would be established (and declarer would know this to be a winner when he sees the ♦J fall, so there's a good case for 3 tricks to declarer.
Suppose you are on the AC. How do you assess this one?