Source: CAC 1976 Bulletin April 1976
There are two sides to every question, it is said, and certainly there are two sides to the Bols Bridge Tip. ‘Watch the early discards,‘ was the advice to declarer. Equally, the defenders should aim to avoid making discards that reveal their distribution. Suppose that this hand is played in a match between two teams:
With both sides vulnerables the bidding goes:
The defenders begin with four rounds of hearts. At the first table dummy throws a club on the fourth heart, East a spade, and South a club. West switches to a diamond, the queen losing to the king.
South, a Bols man, cashes the ace of spades, takes two more diamonds and the K-Q of spades. By this time East has shown up with three hearts and diamonds, and the clear inference from the discard of a spade at trick four is that East began with five. No reason, therefore, to place East with more than two clubs. Declarer plays for the drop and makes his contract. At the second table East also is a Bols man. Judging that the contract will easily be made unless South can be induced to take a losing finesse in clubs, he plans from the first to create the impression that he holds length in clubs. At trick four, instead of the obvious but revealing spade, he throws a diamond. Playing the cards in the same order as before, South arrives at this end position:
Reflecting that East did not throw a spade until he had to find a discard on the third round of diamonds, declarer counts him for 4-3-3-3 distribution and takes the club finesse. Unlucky! Down two.