At most tables in a pairs competition West opened One Diamond and North overcalled with Two Diamonds - the popular Michaels Cue-bid, showing length in both majors. East bid Three Clubs and now South had an intriguing problem.
One approach was to pass, wait until the opponents had run out of steam, then sacrifice in spades at the appropriate level. This usually led to the par result - Six Spades doubled went only three off and East-West had to be satisfied with 500 points.
Another idea was to bid Four (or even Five!) Spades immediately before East-West had established a trump suit. One player bid a dramatic Six Spades and seemed to have achieved a spectacular success when West passed and East, taking this as a forcing pass, soldiered on to Seven Clubs. South, alas, spoilt the effect by leading his singleton heart and the grand slam rolled in.
The heart lead, of course, becomes attractive if East-West have used Blackwood to discover that an ace is missing. If North's ace is in hearts - bingo! One of the best scores went to the South player who, over Three Clubs, introduced Blackwood himself! The idea was that if partner held two aces (presumably in the major suits) there was no need to sacrifice, while if partner held no aces, a save in Seven spades made sense. It was anyone's guess what was going on and eventually South was allowed to play in Five Spades doubled.
East-West game; dealer West North S A K Q J £ H Q 9 7 6 2
D Q 10
A J 5
A J 5
K J 8 7 6 2
Q J $ East 4
K 10 4 3
A K 10 9 6 2
South 9 8 7 6 5 2
9 5 4
8 7 5