As Y has no other card to lead, B should refuse to part with the ace. Z cannot make the suit without two re-entry cards.
TAKING OUT RE-ENTRY CARDS
If you hold the commanding card of the adversary’s suit, endeavour to take out your opponent’s re-entry before the suit is cleared. It is equally important that you take out this re-entry card if you know that your partner has the command of the adversary’s suit. In extreme cases do not hesitate to sacrifice a king or queen in order to accomplish this purpose. When the dealer attempts to make a card of re-entry for an established suit, hold up a higher card in order to frustrate his scheme of play.
THE DISCARD
This part of the game merits much more consideration than a cursory knowledge of Bridge would suggest. The ordinary Bridge player is confused by the many difficulties attendant on discarding, and his cards are apt to be injudiciously thrown away. It would greatly simplify the discard if you were always to throw away your lowest card or to follow some other hard-and-fast rule; but, unfortunately, the discard is so affected by the particular situation and by the previous play as to preclude the possibility of establishing such a rule. When you advise the beginner to throw away a high card instead of a two spot, the situation appears to him hopeless; he fails to realise that at times high cards have little value, and, to obtain the lead, honours and even smaller cards must be properly protected.
When opposed to the dealer, it should be your aim both to protect your hand and to give your partner information. As the eldest hand, your opening lead indicates strength or weakness; any subsequent discard is simply the card that you can best spare, and is not intended to convey any definite information. As the original leader, it is important that you know your partner’s suit, and this information he should convey to you by a recognised system of discarding decided on before beginning the game. Thus the discard from the strength or from weakness refers only to the first card thrown away by the younger hand.
There are three methods of discarding used by Bridge players, each having the same object—to protect the hand and to give information.
1st. Strength both with a trump and at “no-trump.”
2d. Strength with a trump and weakness at “no-trump.”
3d. Weakness both with a trump and at “no-trump.”
Some merit may be claimed for each; but there is a wide difference of opinion regarding the relative values of these discards. In Whist, as well as in Bridge, there has always been more or less discussion on this point. It can, however, be stated that the foremost authorities on Whist have uniformly agreed that with strength declared against you, the best discard is from your strong suit.