The defensive signals in bridge are, in theory at least, not hard to grasp. Top priority goes to attitude. An unnecessarily high card tells partner that you have useful goodies in that suit. When attitude is known or clearly irrelevant, you signal count. You play your lowest card with an odd number, or start an echo (high-low) with an even number. If both attitude and count are known or irrelevant, you send a suit-preference signal. Your lowest card asks for the lower-ranking of the other two side suits, your highest card for the higher-ranking suit.
The really tough part comes when your hand suggests making one signal, but a perusal of the board makes it apparent that it is time to do the opposite.
Look at the North and East hands in the diagram. Your partner leads the heart 10 against South's contract of three spades. What card would you play at trick one?
West bid three hearts in the modern style, showing four-card heart support but a relatively weak hand (nine losers). With a stronger hand, he would have cue-bid two spades.
Normally, you would drop the eight to encourage a heart continuation (or overtake with the jack). Here, though, you should see the advantage in partner's shifting to a diamond at trick two. Play the heart two, discouraging. Assuming partner trusts you, he will lead the diamond 10 next and your side can take six tricks: one spade, two hearts, two diamonds and one club. If instead West plays a second heart, the contract can (but might not) be made.
The really tough part comes when your hand suggests making one signal, but a perusal of the board makes it apparent that it is time to do the opposite.
Look at the North and East hands in the diagram. Your partner leads the heart 10 against South's contract of three spades. What card would you play at trick one?
West bid three hearts in the modern style, showing four-card heart support but a relatively weak hand (nine losers). With a stronger hand, he would have cue-bid two spades.
Normally, you would drop the eight to encourage a heart continuation (or overtake with the jack). Here, though, you should see the advantage in partner's shifting to a diamond at trick two. Play the heart two, discouraging. Assuming partner trusts you, he will lead the diamond 10 next and your side can take six tricks: one spade, two hearts, two diamonds and one club. If instead West plays a second heart, the contract can (but might not) be made.