Deal 12
 
 
 
♠ A J 8 7 5 2
A K
Q 6
♣ J 8 7
 
 WEST  NORTH  EAST  SOUTH
pass1♠pass2
pass2♠pass4♠
passpasspass

North opens 1♠ and South responds 2.
North has a pretty good hand, 17 points, but no stopping power in the minor suits.
Also, North's ♠ suit is pretty ragged. Taking these points into consideration, North should just rebid his 6-card suit.

South should now jump to 4♠. This is Fast Arrival, indicating a minimum hand with no particular interest in slam.

North is happy to rest in the game contract.

Even with a combined 30 points, 10 tricks are certainly not a sure thing.
North must hope that West holds the trump King.

 Deal 13 
  ♠ Q 6 3
Q 3
A K J 9 4
♣ 9 6 4