This real life hand, dealt in a BBO ROBOT IMP tourney provides fascinating scope for double dummy analysis. With best defense, would you care to declare or defend 6NT?
Consider one sample double dummy line on a Diamond lead. Win in hand high, preserving the Ten in dummy. Cash the heart Ace. Advance the SQ, forcing cover all around. Now lead a small heart toward K7. Righty with QJ6 has to split. (If he does not, letting my 7 win, I change horses and build up a club trick by forcing out the king, now 3H+2C+2S+5D =12) Win King and play a heart toward the 98x, establishing a good and long heart (A,K,8, x is 4 heart tricks). East on lead finds that all suits are stopped by declarer, who still has the DT entry, 5Diamonds + 4 hearts + 2 spades + 1 club = 12
Other leads are easier to analyse
So, did you chose to play or defend? What is that? You chose to play? Wrong. The lead of KING of spades prematurely knocks out the dummy entry, leaving you unable to do the fancy trick building footwork in hearts
