The primary point to the play is South's handling of the diamond suit.
South counted 11 tricks, and saw that the 12th would probably have to come from the diamond suit.
How to attack the diamond suit was now the problem.
South captured East's queen with the king and thought about the diamond suit.
The crucial question is the play of the diamond suit.
But North, tempted by his long diamond suit, moved on to five hearts.
West had no reason to know that the lead of the club king would be effective, and led his partner's diamond suit.
The result hinged on whether or not East had an opportunity to show his diamond suit.
Shows a weak hand, 5-9 points, with a long diamond suit.
The players were using a new deck that had two diamond suits and no heart suit.