1. At least 5-5 in hearts and diamonds
You probably didn’t expect to be in slam after your light opener, but here you are. Your partner made two penalty-oriented doubles, but you didn’t like your void in hearts, so you bid 3♠ and quickly found yourself in a 12-trick contract. You get the lead of the ♦K, which you win in dummy. Now what?
As usual, declarer could count 11 tricks against any distribution and 12 if the trumps were an unlikely three-two. After winning the first trick with dummy’s ♦A, declarer played the king and ace of trumps, getting the bad news that East had a trick in the suit. Declarer ruffed a diamond then cashed the ♣K. The ♣Q was overtaken with the ace. When West discarded a diamond, declarer paused to think.
It was clear from the auction that East had longer hearts than diamonds; otherwise he would have bid 3♦ instead of 3♥. Declarer surmised that West began with 1=5=6=1 shape and East with 4=3=2=4 distribution. So, declarer cashed the queen of trumps and played two more rounds of clubs, reducing everyone to four cards. Declarer now played his last club. East threw a heart because he saw that there was no point in ruffing. If he did ruff, he would have had to lead a heart, allowing declarer to take the last three tricks with two hearts and a trump.
However, the heart discard served only to delay his fate because for declarer now led a trump, throwing dummy’s remaining low heart. East got his trump trick but dummy’s ♥A and ♥Q had to take the last two tricks.
Of course, if West had followed to the second club, he would have been marked with 1=5=5=2 shape, so a second diamond could then have been ruffed safely in dummy. The ♥A would have taken care of declarer’s last diamond and all declarer would have lost would have been a trump trick. The full deal: