Brad Moss and Joe Grue did well to reach the diamond slam here, playing for the Rubenstein team against Ventin in the Spingold quarterfinals. Moss still had to time the play well, though, to bring it home. Cover up the East-West cards and see how you would handle it.
West leads a spade after East has shown both majors in the auction, East contributing the king. What is your plan?
Start by assuming trumps are not 4-0 — you cannot make it against that. You must run dummy’s clubs, but you need only five tricks from the suit and can afford to ruff them if you must. You must be careful with your entries, though. The key is that you must retain the diamond queen as an eventual reentry to dummy.
After winning with the spade ace, cash the diamond ace and king. When East shows out on the second round, you should abandon trumps for the time being and start on clubs. You take the club queen first so as to not block the suit. Then you lead a club to the ace; there is no need to risk a finesse. If the suit breaks, simply draw trumps and claim your 13 tricks.
When East discards, you can demonstrate why your precautions were necessary. You ruff a club to establish the long cards. Then you get back to dummy with the diamond queen, drawing the last trump, to enjoy the club suit. Twelve tricks are yours.
This is how Moss played the hand to earn a swing for his team, who went on to win the match comfortably.