Deal 18
 
 
 
♠ K J 2
8 7 4
A Q 9 7 5
♣ Q 2
 
 WEST  NORTH  EAST  SOUTH
1♠
pass2pass3
pass4♠passpass
pass

South opens 1♠.
North responds 2, a 2/1 force to game.

South cannot rebid her ♠s, but has decent support for partner's s.
So she bids 3.

North always intended to play a ♠ contract.
He now bids 4♠, using Fast Arrival to indicate he has no slam aspirations.

4♠ is cold, and if the defenders don't take their tricks immediately South will make an overtrick.

 Deal 19 
  ♠ A Q 10 9 5
10 9 6
K 10 8 6
♣ A