Be particularly conservative in doubling a “no-trump” make; for but rarely does it pay to double with a hand containing general strength. Remember that while you are in the dark as to your partner’s hand, the dealer has the enormous advantage of seeing and combining his own hand and the dummy; that he knows what suit to avoid, and what suit to establish; and that your doubling will place him in a still more advantageous position by enabling him to locate honours and make successful finesses. Be cautious, also, when you hold fair strength in three suits and are weak in the remaining one. The maker is apt to hold a very long suit and you will not find it easy to discard, and at the same time protect your hand.
Usually it is not safe to double a “no-trump” make unless you hold a suit that you are reasonably sure is established. It is a gamble to double with a six-card suit headed by ace, king, and queen with no other trick in the hand. You depend on your partner to take one trick, which he may not be able to do; and, should you find your long suit protected in the adversaries’ hands, you run the risk of being very badly beaten. If the odd trick wins the game for the adversaries and does not win it for you, such a double may be justifiable; still you cannot hope to win more than 24 points by doubling, and you risk losing three or four odd tricks with a possibility of a redouble. While such a double will often succeed it can hardly be classed as sound.
As the younger hand, it may be wise to double a “no-trump” make in order to prevent great loss or to save the game. In other words, it may pay to show your partner by a double that you have strength in a particular suit. There are at present two methods used by Bridge players to indicate this strength, one known as the Heart Convention and the other as the Weak Suit Convention.
REDOUBLING
Although the score may sometimes warrant a redouble without extraordinary strength, a redouble practically avows the ability to take six, and probably, seven tricks. In estimating your hand consider the possibility of finding all the remaining trumps in one hand, and do not value honours in the side suits too highly, for if he holds great trump strength the maker is probably short in the other suits. A redouble at “no-trump” indicates protection in every suit.
The dealer should often redouble, not so much on the strength of his hand, but to the score; knowing that should the adversaries win the odd trick the game is lost, and that his redouble will equalise the situation and make it possible for the odd trick to win the game for either side.
ESTIMATING THE VALUE OF A HAND
In considering your probable tricks those in the trump suit are of course most certain.
On the right side of the maker three trumps with a single honour, ace, king, or queen, may be estimated as being worth but one trick.
Do not count on ruffing with a single trump.