One of the most difficult aspects of playing bridge is defense. If you improve your defense, you will automatically upgrade your game.

Work as a partnership on defense and you will have a huge advantage over players who shirk this part of the game, thinking that they need to learn more conventions.

Defense involves logic, making the right lead and signaling correctly to your partner. To be a good defender you have to look beyond the trick you are playing and look at the whole picture.

The most important part of defense is making the “killer lead.” Rules for leading to No Trump and to Suit contracts are different.

No Trump is a race. The defenders are trying make tricks for their side while the declarer tries to make tricks for his side. The defenders have an edge because they get to lead first.

In order to take advantage of this edge, you must choose your opening lead wisely. It doesn’t matter if you win tricks early or late in the hand; it’s only important that you win as many tricks as possible.

A basic rule for choosing the opening lead is to lead partner’s bid suit unless you have a lead that is clearly better. Suppose your partner bid hearts and you are on lead against 3 NT. You could have the following holdings in hearts: 92 J103 K76.

Let’s practice.

With 92, lead the 9; with J103, lead the J; and with K76, lead the 6.

Try one more: The opponents are in a 3NT (1NT-3NT) contract with no bids by partner. You have A9742 of spades and K8632 of hearts. With two long suits, both headed by an honor, it is best to lead the one without the Ace.

This way if you manage to set up the hearts, then you will have the Ace as an entry to get in to play your hearts. If you lead a spade and set up the spade suit, the King of hearts may not be an entry.

What would you lead against a NT contract with these holdings?:

1. KQ64

2. AKQ32

3. KJ10943

4. KQ1074

5. Q7643

Dr. Kathie Walsh, an ABTA teacher of the year, teaches all levels of bridge at Hilton Head Island Bridge Club.