King Charles I of England said, "Never make a defense or an apology until you are accused." That's an interesting comment from a king who was accused of being a "tyrant, traitor, and murderer," and who three times refused to plead at his trial.
    At the bridge table, defense is the toughest skill. But there are some key agreements that, when followed, can turn apparent guesses into certainties. This deal highlights one of the most important. First, look at only the North and East hands. Against three no-trump, your partner leads his fourth-highest spade, South capturing your jack with his king. Now declarer plays a low diamond from his hand. West wins immediately with his ace and shifts to a heart, your ace taking the trick. Do you return a spade or a heart?
    West did well to win trick two. He knew from the first trick that South had the ace and king of spades. And he could see those six club tricks sitting on the board. So, if declarer were permitted to sneak a diamond trick, he would run for home. And the defenders had to take four heart tricks immediately.
    If West started with five spades headed by the ace-jack, East must return a spade. But with this layout, East must play back a heart, giving the defenders four hearts and one diamond.
    The key comes from the heart that West leads. Here, he selects the two, his lowest one. This says, "Partner, I have honors in hearts and am trying to get tricks from this suit." If West had weaker hearts and strong spades, he would shift to a high heart, not his lowest.