By Barbara Seagram 
Courtesy of BarbaraSeagram.com
We may not all agree with the bidding but this is how it went with the particular pair that bid this. Since a trump suit had not been agreed upon, the pair used old-fashioned Blackwood to arrive at 6♥.
South realized that if he lost a club trick, he would be down one. He decided to postpone playing the club suit and tried to get more information.
West led the ♠A, followed by the ♠K. South ruffed and crossed to dummy with the ♥Q. He led the third spade from dummy and ruffed it in his hand.
DISCOVERY: West started with SEVEN spades and East started with TWO spade.
So let’s focus on counting the West hand. It is always easier to count a hand that has one very long suit. South led more trumps. On the second round of trumps, East failed to follow. DISCOVERY: West started with three hearts (and seven spades).
Declarer drew West’s last trump and now started on the diamond suit. On the third round of diamonds , West failed to follow. DISCOVERY: West started with two diamonds (and three hearts and seven spades). That meant that West could only have one club.
Declarer now played the ♣A, led a small club from dummy and played the ♣10 from his hand, KNOWING that West could not have another club. Moral of this story: When you have a problem suit and a finesse has to be taken, postpone playing that suit until you have played the other suits and managed to glean more information about how many cards the opponents hold in those suits. That will ultimately reveal how many cards are in each hand in the problem suit and will help you know how to play that suit.