THE DISCARD
There is considerable discussion and a wide diversity of opinion among Bridge Players as to the best suit to throw away. You should, therefore, before playing, ask your partner which method he adopts. Some advantage may be claimed for each theory of discard; but the main object of them all is the same—to indicate to partner the suit you wish led and at the same time protect any honours you may hold in other suits.
The three different discards used by Bridge Players are:
Strength, both with a trump and at "no-trump."
Strength, with a trump and weakness at "no-trump."
Weakness, both with a trump and at "no-trump."
The discard of strength with a trump and weakness at "no-trump" is the one most commonly used. This discard of weakness at "no-trump," while it has the advantage of saving all the cards of the long suit, which you may make, has also several disadvantages.
To show your suit absolutely you need two discards.
In order not to deceive your partner it may be necessary to unguard honours, such as J x x x, 10 x x x, Q x x, or even K x.
By discarding weakness you show the dealer against which hand to finesse.