Negative free bid is a contract bridge

Contract bridge

Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...

 treatment whereby a free bid by responder over an opponent's overcall shows a long suit in a weak hand and is not forcing. This is in contrast with standard treatment, where a free bid can show unlimited values and is unconditionally forcing. The treatment is a relatively recent invention, and has become quite popular, especially in expert circles.

Negative free bids resolve relatively frequent situations where the responder holds a long suit with which he would like to compete for a partscore, but is deprived from bidding it by opponent's overcall.

Example

West	North	East	South
|1	1	?

For example, if South holds: , partner opens 1 and East overcalls 1, he couldn't bid 2 in standard methods, as it would show 10+ high-card points

Hand evaluation

In contract bridge, various bidding systems have been devised to enable partners to describe their hands to each other so that they may reach the optimum contract. Key to this process is that players evaluate and re-evaluate the trick-taking potential of their hands as the auction proceeds and...

, and a negative double

Negative double

The negative double is a form of take-out double in bridge. It is made by the responder after his right-hand opponent overcalls on the first round of bidding, and is used to show both support for the unbid suits as well as some values. It is treated as forcing, but not unconditionally so...

 would be too off-shape. With NFB treatment in effect though, he can bid 2 which the partner may pass (unless he has extra values and support, or an excellent suit of its own without tolerance for hearts).

However, as a corollary

Corollary

A corollary is a statement that follows readily from a previous statement.In mathematics a corollary typically follows a theorem. The use of the term corollary, rather than proposition or theorem, is intrinsically subjective...

, negative free bids affect the scope of negative double; if the hand is suitable for "standard" forcing free bid (10-11+ points), a negative double has to be made first and the suit bid only in the next round. Thus, the negative double can be made with the following types of hand:

• A weakish hand with unbid suits (unbid major)
• A stronger hand with unbid suits
• A strong (opening bid or more) one-suited hand.

This can sometimes allow the opponents to preempt

Preempt

Preempt is a bid in contract bridge whose primary objectives are to thwart opponents ability to bid to their best contract, with some safety, and to fully describe one's hand to one's partner in a single bid. A preemptive bid is usually made by jumping, i.e. skipping one or more bidding levels...

 effectively.

West	North	East	South
1	1	Dbl	4
?

For example, West, holding: , after this auction is in an awkward situation — he doesn't know whether partner has spades or not; whether South was bidding to make or to sacrifice

Sacrifice (bridge)

A sacrifice is a deliberate bid of a contract in duplicate bridge that is unlikely to make in the hope that the points will be less than the points likely to be gained by the opponents in making their contract...

— is it correct to double, bid 4 or pass?

External links

• Alan Truscott's column in New York Times
• Detailed description