The Monaco convention was the original relay-based bidding method. It was devised by Mr. Pierre Ghestem , (Monsieur Pierre Ghestéme) of France around the year 1945. Mr. Pierre Ghestem was born February 14, 1922 and died April 11, 2000, of France. Together with his long-time regular partner, Mr. René Bacherich of Lille, France, they employed the bidding method in several World Championship tournaments such as the 1956 Bermuda Bowl championship played in Paris, France, when they won the Bermuda Bowl Trophy with team mates Mr. Pierre Jaïs, Mr. Robert Lattés, Mr. Bertranm Romanet, and Mr. Roger Trézel.

Note: Monsieur Pierre Ghestéme was also the holder of the coveted title of World Champion of Checkers from the year 1945 to the year 1947. Source.

They placed second, using the same relay-based system, at the 1954 Bermuda Bowl championship played in Monte Carlo, Monaco, with team mates Jacques Amouraben of France, Jean Besse of Switzerland, Marcel Kornblum of France, and Karl Schneider of Austria.

Newspaper Comment: January 19, 1992, by Mr. Alan Truscott in his Bridge Column for The New York Times in .pdf file format.

Mr. René Bacherich of Lille, France, was born in the year 1906 and died in the year 1997. During his bridge career he attained the designation of World Bridge Federation World Life Master. He assisted and supported Mr. Pierre Ghestem with the development of this relay-based system and also the relay-based Monaco system, among other similar contributions.

Perhaps it is of note that a better description than original would be the adjective prototype in describing this relay-based system, since this relay system was only an experiment to discover the merits of the system in international tournaments. Had the relay system not been successful, then bridge history may have taken another course and would have been written differently.

he main concept of the relays some transfers is to bid in such a manner as to make the stronger hand become the declarer in the final contract. Below is an overall description of the Monaco bidding system.

The opening bids are shown in the following schematic, with additional explanations following.

• 13-23 high card points Shows a 3-card plus Club suit; can be a 2-card Club suit.
• 13-18 high card points Shows a 4-card plus Diamond suit.
• 10-17 high card points Shows a 4-card plus Heart suit.
• 10-17 high card points Shows a 5-card plus Spade suit.
• 18-20 high card points Balanced shape.
• 24+ high card points Various shapes.
• 19-21 high card points Shows a 5-card plus Diamond suit.
• 18-21 high card points Shows a 5-card plus Heart suit.
• 18-21 high card points Shows a 5-card plus Spade suit.
• 18-21 high card points Balanced shape.

Structure of the Monaco Convention

Opening Bids

One Club Openings

All 1 Club openings show 13 to 23 high card points or distribution of 4-4-3-2. This opening also shows no 5-card Major suit or 4-card Diamond suit.
If the opener has 18 to 22 high card points, then the opener is expected to open 1 Club and rebid by jumping a level in another long suit.

One Diamond Openings

A 1 Diamond opening shows 13 to 23 high card points, a 4+ length in Diamonds, no 5-card Major suit, or a balanced hand with opposite variable 1 No Trump hand.
A 1 Heart response is a relay, and a rebid by the opener of 1 No Trump shows the opposite variable 1 No Trump holding. A jump in No Trump by the opener would show maximum values.
All other bids are then natural and are not forcing above 2 Clubs.

Major Suit Openings

Any Major suit opening shows 10 to 17 high card points and a 5-card suit. The cheapest response is a relay. This relay and any subsequent relay is asking partner to clarify and describe his holding further.

A 2 Club response is natural and forcing.
A 2 No Trump response shows a 3-suited hand containing a void in the suit of the opener.
Any response at the Two Level are transfer responses.
Any other response is natural and not forcing.

Variable No Trump Openings

Using the variable No Trump, a 1 No Trump opening shows 13 to 15 high card points when not vulnerable, and 18 to 20 high card points when vulnerable. The opener first bids 1 Diamond and then rebids 1 No Trump with the opposite variable 1 No Trump holding.

A 2 Clubs response is a relay.
A 2 No Trump response shows a 5-card Club suit.
A 2 No Trump response is also a Second Relay.
Suit responses are generally considered Transfers.

Strong 2 Clubs Openings

A 2 Clubs opening shows 24 plus high card points, any distribution, and is forcing to game.

A 2 Diamond response is negative.
A 2 Heart response shows 1 Ace or 4 Kings.
A 2 Spades response shows 2 Aces or 3 Kings.
A 2 No Trump response shows 3 Aces or 2 Kings.
Any other response is a natural, but negative response.
Any relay bid by the opener asks for further descriptive information, and a Super Relay, or skipping a bid, is an Asking Bid.
Any Jump rebid by the opener is limited.

Suit Openings on the Two Level

Any Suit opening on the two level shows between 18 and 21/22 high card points, a 5-card plus suit, less than a 3-card Club suit. With a 3-card plus Club suit, the opening is 1 Diamond.

Any response at the Three Level is a transfer.
A 3 Clubs rebid by the opener after a relay by partner shows maximum values.

Responses to 1 Club

A 1 Diamond response is either a negative, showing 0 to 7 high card points, followed by a pass or a weak rebid, or shows 10 to 11 high card points, followed by a jump in Diamonds or No Trump, or shows a game-going relay, 11 plus high card points, followed by a Second Relay of jump to game.
The opener can use a relay of 2 Diamonds showing 18 plus high card points, which asks the partner to further describe his holding.

A 1 No Trump or 2 No Trump response is natural and limited.
A 2 Diamonds, 2 Hearts, or 2 Spades response is a Weak Transfer, signifying 4 or 5 playing tricks.
Any response of 3 of any suit indicates 6 playing tricks.

Relays After 1 Club

A 1 Diamond response is either a negative, showing 0 to 7 high card points, followed by a pass or a weak rebid, or shows 10 to 11 high card points, followed by a jump in Diamonds or No Trump, or shows a game-going relay, 11 plus high card points, followed by a Second Relay of jump to game.
The opener then relays with 1 Heart, showing 4 Hearts, or the opener relays with 1 Heart, showing 4-4 in the Majors.
The opener then relays with 1 Spade, showing 4 Spades.
The opener then relays with 1 No Trump or with 2 Clubs with no 4-card Major suit.
If the responder has a strong hand and requires additional information regarding the holding of his partner, then the responder continues to relay with 2 Diamonds, and then with 3 Diamonds or 3 Hearts.

Summary of the Relay System

The following diagram of the bidding sequences with the corresponding significance of the bid, relay, or transfer should clarify the Monaco system to a larger degree. It should be understood that the bidding system contains the requirement, that any rebid by the responder of 3 Diamonds or 3 Hearts forces the opener to rebid 3 No Trump. The attempt has been made to make the presentation understandable.