North: ♠QJ108 ♥Q1096 ♦108 ♣AK8
South: ♠A9764 ♥53 ♦KQ63 ♣74
South passed. West opened 1♦. North doubled for takeout. East bid 1♥ and South bid 1♠ (which only promises 4 cards opposite a takeout double). West bid 2♣. North bid 2♠. East bid 3♣ and South correctly took the push to 3♠, having an extra trump— and shortness in clubs, and also expecting partner to be short in diamonds.
The lead was the ♣Q. Your contract is fairly safe. You will lose two heart tricks and one diamond, expecting to ruff two diamonds in Dummy. You may or may not lose a trick to the ♠K. Once Dummy comes down, you note that the opponents' clubs must be 4-4 from the auction. LHO (West) must have five diamonds. Since the opponents have only 19 HCP between them, those points are likely to divide 12-7 or 13-6. Both opponents have taken two bids with relatively few points, so expect either appealing quick tricks or some distribution somewhere. West is a likely candidate for a singleton. When a bidder opens a diamond and rebids 2♣, he promises at least 9 cards in the minors and usually has a singleton. [Once in a great while, the bidder will be 4-1-4-4 or 1-4-4-4, but you know that is not the case here.] So you suspect that West MIGHT have a singleton spade.
Before you decide about the spade finesse, it costs nothing to lead a low heart from Dummy. If East ducks and West wins cheaply, you won't have learned anything. (When you win the second club, you will play a diamond from Dummy.) In this case, however, East will win the ♥K—revealing that East owns both the ♥A and the ♥K. Now you know that West MUST have the ♠K for his opening bid, so you won't be taking the finesse. After you force out the ♦A, you will cash the ♠A, hoping for a singleton ♠K—which works. Making 4!
West: ♠AK9 ♥AQ106 ♦106 ♣K1073
East: ♠7 ♥K ♦AK52 ♣AQJ9864
The auction was a bit confused at our table. I would recommend the following sequence (opponents passing throughout). 1♣ 1♥; 2♦—yes I know you are 7-4, not just 5-4, but it puts both your suits in play, and the reverse states your strength well. Now partner can bid 3♣ which shows a good hand (Lebensohl over reverses). 4♣ would be Minorwood. West respond will 4♥ (1430) to show all three missing Key Cards—the ♠A, the ♥A, and the ♣K. My agreement with partners is that if the answer does not mention the Queen of trumps, the next suit up (4♠ in this case) is Queen ask. 4NT is normally a sign-off, as would be 5♣. So, 5♦ becomes the King ask—and confirms possession of all five Key Cards AND the Queen of trumps. Partner will bid 5♠ (specific King if you play that, or one King if you play number of Kings). At this point, East can count 13 tricks: seven clubs; two diamonds; two hearts; and two spades. So, the correct bid is 7NT.
In the open game, one pair played in 5♣, making seven; one pair in 3NT, making seven; three in 6♣ making seven; and one in 7NT (making seven). In the limited game, 7 pairs were in 5♣; 2 were in 3NT; 5 were in 6♣; 3 were in 6NT; and one pair was in 7NT.