Deal 20
 
  6♠
OL: J
♠ K Q 10 3
J 8 7 4
A 3
♣ A K 7
 
 WEST  NORTH  EAST  SOUTH
1NTpass3♠
pass6♠passpass
pass

You are West. The bidding has been as shown.

You lead the J and dummy's A wins the first trick.
Declarer pulls trumps with dummy's ♠K, then his ♠A.
He then plays his K and follows with ♣Q, ♣K and ♣A, discarding a from his hand on the last.

With all that completed South plays the A.
What do you play?

When you have made your choice click NEXT .
♠ 8 4
K 5
J 10 9 5 4
♣ 9 8 6 2
♠ 7 2

6 2
♣ 10 5 4
  ♠ A 5
A 2
K 7
♣ Q 3
 

 
Deal 20
 
  6♠
OL: J
♠ K Q 10 3
J 8 7 4
A 3
♣ A K 7
  Play the K.

It may look foolish to waste your K but look what will happen if you don't.
South will follow up with another and when you win the K you will be forced to play a minor suit. Since both North and South are out of s and ♣s you will be giving them a ruff-sluff and the contract.

But if you dump your K under South's A look at what's left.
South has losers and when he plays a from either hand East will scoop up two tricks with his Q 10.

 To Lesson 
♠ 8 4
K 5
J 10 9 5 4
♣ 9 8 6 2
♠ 7 2
Q 10 3
Q 8 6 2
♣ J 10 5 4
  ♠ A J 9 6 5
A 9 6 2
K 7
♣ Q 3