Defensive signals

Attitude: the first one to learn

When partner leads a suit and you can't beat what's been played, your card says whether you want the suit continued.

A high spot card encourages. A low one discourages. Holding ♥ 8 3, play the 8 if you like hearts and the 3 if you don't.

"High" and "low" are measured against the cards you hold. The 6 from ♥ 6 2 is encouraging; the 6 from ♥ Q 9 6 is not.

Count: when declarer is running a suit

When declarer leads a suit, you rarely have an opinion worth giving, so your cards show how many you hold instead.

High-low means an even number, low-then-high means odd. With ♦ 8 4 you play the 8 then the 4; with ♦ 8 6 2 you play the 2 first.

Partner uses it to work out declarer's length, which tells them when to take an ace. Holding the ace, they wait until declarer plays their last card in the suit, so dummy's long suit can't be reached.

Suit preference

Sometimes neither attitude nor count helps. The clearest case is giving partner a ruff: they'll trump it either way, and what they need to know is which suit to lead back.

The card you give them says which of the two other suits you want. A high card asks for the higher-ranking, a low card for the lower.

Hearts are trumps, you give partner a club ruff, and they must return a spade or a diamond. Your highest club asks for the spade; your lowest asks for the diamond.

Which signal is this?

Knowing all three doesn't help if partner can't tell which one you just gave. The order of priority is nearly always:

1. Partner led and you have an opinion: attitude.
2. Declarer led: count. You have no opinion worth giving about a suit declarer chose.
3. Attitude and count are both pointless: suit preference. A ruff, a trump suit being drawn, or a singleton in dummy.

Discards follow the same logic: the first discard is usually attitude about the suit you're throwing.

Upside-down signals

Many partnerships reverse attitude and count: low encourages, and low-high shows an even number.

The argument is that encouraging with a low card keeps your high spot cards, which can be worth a trick. The cost is that standard is usually taught first, so a pair who haven't agreed which they play can misread each other.

Neither method is clearly better. Both of you need to know which you're playing, and the opponents must be told when they ask, since they're entitled to know your carding agreements.

Three signalling mistakes

1. Signalling with a card you need. Don't give up a trick to signal. Throw the useless card and let partner work it out.
2. Encouraging with nothing. A high card with no honour or shortage behind it can cost partner a trick when they continue the suit.
3. Giving declarer information. Declarer can read your signals as well as partner can. If partner can't use the information, don't give it.