He sat West, and led the club king after his opponents bid aggressively to six spades.

He was looking at one jack, and was not in the least surprised when his opponents bid their way to six diamonds.

South landed in six hearts after his opponents had bid to five diamonds.

He sat West and heard his opponents bid aggressively to seven spades.

He sat West and heard his opponents bid to four spades by a natural route.

If your opponent ever bids in a totally extraordinary fashion, watch out.

The opponents have not bid, and the club ace is led.

Suppose the opponents have not bid and the ten holds the first trick.

If he had simply raised his partner's heart suit the opponents would have bid spades at least to game.

If the opponents have bid two suits there is no need for any cue-bid.