for a return from partner what is considered a high card (high encourages we
like the suit)?
Well, this is
one of those "it depends" topics. A determination of what is a "high" card
varies depending on several factors:
1. The suit rankings in your
If you hold:
Q J 6 5 4 3
And Dummy tables:
8 7 2
Then your partner's 8
is likely discouraging.
2. The values in the Dummy -
3. Inferences in the bidding - if you and partner bid a suit, your side
obviously has a wider range of cards to signal in that suit. There are
numerous variations of this theme.
4. Whether the auction is in a suit or Notrump - it should be
obvious that if opponents are in a major suit game or slam,
your side can afford to discard a higher card to signal than
if the opponents are in a 1 Notrump contract.
5. Inferences during play, as opening lead, declarer and defender play, etc
none of the above mattered. In that situation, the
5, 6, and 7 are generally considered "neutral" cards, with
higher cards encouraging and lower cards discouraging.
even go so far as to distinguish between a 2 and a 3 as
attitude signals when partner knows the suit was supported during bidding.
But these situations are very partnership dependent. Here's some
good books on