The Owosso Argus-Press – 20 Jun 1963
North and South vulnerable; South dealer
Opening lead: 
4
As North put down his hand as dummy he remarked. «Well partner, you sure trapped me beautifully. You couldn’t act over East’s five heart bid and then when I chose to bid five spades you went right to six.»
South did not reply. He was waiting for East’s lead on the second trick.
When East continued hearts. South ruffed, drew trumps and claimed his slam. He still did not bother to answer North. Success had answered for him.
In most instances a bid that traps your partner should be avoided, but there are exceptions and South’s pass over five hearts and bid of six spades were both logical.
South had used that rare bid: the forcing pass. He had decided that if he bid five spades his partner would probably be unable to go to six because he South, was looking at a singleton heart and North might well hold a couple of cards in that suit.
South also decided that if North doubled five hearts it would show heart strength, in that case South might not even make five spades and it would be better to play at five hearts doubled.
However, North did bid five spades. South was sure that all North’s high cards would be working spades and South bid the slam with every expectation of success.