In the game of 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...

, Ghestem is a conventional overcall

Overcall

In contract bridge, an overcall is a bid made after an opening bid has been made by an opponent; the term refers only to the first such bid. A direct overcall is a bid made directly over the opening bid by right-hand opponent; an overcall in the 'last seat' is referred to as a balancing...

 structure, utilising 2NT, 3, and the (non-jump) cuebid over an opposing opening at the one level to denote two-suited hands in two of the remaining three suits.

This convention was devised by the French bridge and checkers player Pierre Ghestem

Pierre Ghestem

Pierre Ghestem was a French bridge and checkers player. In 1947 he became the world champion in checkers...

.

When playing Ghestem, after an opposing one-level opening, the three overcalls mentioned denote the three possible two-suited hands in the suits excluding the opened suit:

2NT : shows the two lowest ranking unbid suits

3 : shows the two highest ranking unbid suits

Cuebid : shows the top and bottom ranking unbid suits

Requirements

The requirement for a Ghestem overcall

Overcall

In contract bridge, an overcall is a bid made after an opening bid has been made by an opponent; the term refers only to the first such bid. A direct overcall is a bid made directly over the opening bid by right-hand opponent; an overcall in the 'last seat' is referred to as a balancing...

 is a two-suited hand with at least 5 cards in each suit

Suit (cards)

In playing cards, a suit is one of several categories into which the cards of a deck are divided. Most often, each card bears one of several symbols showing to which suit it belongs; the suit may alternatively or in addition be indicated by the color printed on the card...

 and opening values. Point counts vary, but it is commonly agreed that a Ghestem bid is constructive and should be made on hands that hold the prospect of winning the auction. If made on very weak hands, there is the danger that if the opponents win the auction they will also have been warned about the distribution of the Ghestem bidder's hand. Given that the Ghestem overcall

Overcall

In contract bridge, an overcall is a bid made after an opening bid has been made by an opponent; the term refers only to the first such bid. A direct overcall is a bid made directly over the opening bid by right-hand opponent; an overcall in the 'last seat' is referred to as a balancing...

s are forcing

Forcing bid

In the card game contract bridge, a forcing bid is any bid that obliges the partner to bid over an intermediate opposing pass. Owing to the partnership's bidding system or a bridge convention, partner must "keep the bidding open", i.e...

, many partnerships apply no upper limit to the high card strength.-

Responses

Invitations are made via jump support bids at the three level (if available), cue bids denote slam interest, a bid in the fourth suit is to play, as are direct game bids. For instance:
- 2 - (pass) - ??

2 : to play (misfit)

2 : weak support bid

3 : weak support bid

3 : invite with spades as trump suit

4 : to play

3 : slam interest

Following responder's cuebid, the Ghestem bidder makes a relay bid in the next strain, and the bidding continues with the responder indicating the trump suit:
- 2 - (pass) - 3 - 3 - (pass) - 4 : slam interest with club support

Advantages and disadvantages

The advantage of Ghestem is that a single bid uniquely specifies the two suits of the overcaller.

This advantage is gained at the cost of losing the natural 3 jump overcall. Another potential drawback of the use of 3 to denote a two-suited hand is that it is prone to partnership misunderstandings. Also, by utilizing 3 over an opposing minor opening to denote the two majors, obviously the two major suits cannot be introduced at the two level. Alternative methods such as Michaels cuebid

Michaels cuebid

The Michaels cuebid is a conventional bid used in the card game contract bridge. First devised by Mike Michaels of Miami Beach, it is an overcaller's cuebid in opponent's opening suit and is normally used to show a two-suited hand with at least five cards in each suit and eight or more points.After...

 do allow for this.

Variations

Given that over a 1 opening the majors have to be introduced at three level, many partnerships who play Michaels have agreed that over an opposing 1 opening a modified structure applies that retains the availability of a natural 3 overcall:
- ??

2NT : shows the lowest two unbid suits

2 : shows the top and bottom suits (i.e. blacks)

3 : natural

3 : shows the major suits

To overcome the problem of having to introduce the majors at the three level over an opposing 1, and in order to retain the natural (1)-2 overcall (indicating a good 5+ card suit), some partnerships also apply a modified structure over 1:
- ??

2NT : shows the lowest two unbid suits (i.e. reds)

3 : shows the pointed suits

2 : shows the majors

2 : Natural, lead-directional (like a 2 overcall over a 1// opening)

A modified structure that allows the partnership to introduce the majors at the two-level after both minor suit openings is attributed to Garozzo

Benito Garozzo

Benito Garozzo is one of the most famous bridge players in the history of the game. He has won 13 world championship titles with the Italian Blue Team, playing with Pietro Forquet and later Giorgio Belladonna...

:
- ??

2NT : shows the lowest two unbid suits

2 : natural

2 : shows the major suits

3 : shows the top and bottom unbid suits (over 1 non-forcing)

Notice that in this variation of Ghestem following a 1 opening, one retains the option to make a natural 2 overcall. As (1) - 3 is non-forcing, partnerships playing Ghestem à la Garozzo use (1) - 3 to introduce very strong black two-suiters.