The Attitude Signal
Part 1 of a 3-part series on basic defensive signals
The general idea of the attitude signal is simple. When partner leads and you follow suit, a high card says you like the suit and can stand a continuation. A low card is discouraging and suggests a shift..
Your ♣A (or the king, if that's your agreement) wins. How do you continue?
Why not get partner's input? If he signals encouragement with a high card, you probably ought to continue.
If this were the entire hand, partner would play the ♣8. You could tell this was high and would continue with the king and another for down 1. Any other lead lets Declarer pitch a losing club on a diamond.
But suppose this were the layout.
Here partner would play the ♣5, which you can tell is the lowest. This does not tell you what you should lead. It just says partner doesn't like clubs. [Reread this paragraph after you study Suit Preference in part 3 of this lesson series. The ♣5 is NOT suit preference.] Of course, it's pretty clear there is no hope in diamonds. If partner has the ♦A, it isn't going anywhere. So your best hope is hearts.
This switch lets you collect your heart trick before Declarer can pitch his heart loser on either the ♣J or a diamond.
One other note. While this hand does not illustrate it, your first discard in a suit – no matter which side is leading – is usually an attitude signal toward the suit discarded. A high discard says you like the suit. Discarding a low card in a suit implies you don't like it. For example, if you discard a high club when hearts are lead, you have something worthwhile in clubs.
The source for all hands in this lesson is Partnership Defense in Bridge, by Kit Woolsey, pp 5-10. [This is a great book on defense but aimed at experienced players.]