When a declaration by the dealer is followed by two passes and an overbid by the right-hand adversary, the dealer is frequently placed in a doubtful position as to whether he should advance his own bid. Some authorities contend that with less than six tricks he should wait for his partner, and while no inflexible rule can be made to cover all such cases, the follower of this proposition has probably adopted the safest guide.
When the original call has been one No-trump, it is the part of wisdom with less than six tricks, even if the adverse suit be stopped twice, to give the partner a chance. If he can furnish more than two tricks, he will declare, and the Dealer can then, if he so desire, continue the No-trump, but to bid without first hearing from the partner is obviously venturesome. If the Dealer have five tricks, that is enough to save game, but is three tricks short of making two No-trumps.
When the Dealer has declared a strong No-trump with one unprotected suit and his right-hand adversary calls two in that suit, it is manifestly unwise to continue the No-trump. Holding six sure tricks in a higher-valued suit or seven in a lower, it is probably wise to bid two or three, as the exigencies of the case may require, in that suit.
In close cases, when advancing or declining to advance the partner's bid, the personal equation should be a most important, if not the deciding, factor. Some players are noted for their reckless declaring; with such a partner the bidding must be ultra-conservative. Other players do not regard conventional rules in their early declarations. The bids of a partner of this kind should not be increased unless the hand contain at least one trick more than the number that normally would justify an advance.
When playing against a bidder who has the habit of overbidding, full advantage should be taken of his weakness, and whenever possible he should be forced to a high contract he may be unable to fulfil.
When a dealer who has opened with one Spade, or any other player who has passed the first round, subsequently enters the bidding, he gives unmistakable evidence of length but not strength. This is a secondary declaration, and the maker plainly announces, "I will take many more tricks with this suit Trump than any other; indeed, I may not win a trick with any other Trump."
Overbidding a partner's secondary declaration, or counting upon it for tricks when doubling an adversary who has overcalled it, shows inexcusable lack of understanding of the modern system of declaring.
WHEN TO OVERBID THE PARTNER
Overbidding a partner with a declaration which he has once taken out is only authorized by an honor count which is of material value, or a sure game. For example, if a player declare one Royal, holding four or five honors, and the partner overbid with a No-trump, the original declarer should bid two Royals; but without the big honor count it is wiser to let the No-trump stand, as the partner has announced weakness in Spades.
The same line of reasoning should be followed when the partner has called two of a suit over a No-trump. As a rule, under these conditions, it is most unwise for the original No-trump declarer to bid two No-trumps, but with four Aces, the value of the honors thoroughly warrants such a declaration, unless the partner's call has evidently been a "rescue."