Mr. Oswald Jacoby, together with his son Mr. James Jacoby, devised these opening bids during his bridge career with certain established requirements for the bridge player. As a bridge theorist, author, and instructor the intention was that these opening bids become standard. However, the concept of opening a 4-card Major suit was eventually replaced with the concept of a 5-card Major suit.



These opening bids were published in their book Win at Bridge With Jacoby Modern: The System for the Seventies, published in 1970 by Enterprise Publications in New York, New York, United States, ISBN B00070HQ78. For a summary of these opening bids in addition to a summary of the continuances, please visit the website of Mr. Jim Loy, dated 1996.

Opening Bids Only

Bid Strength Meaning
1 : 12-21 high card points Shows 4 plus Clubs.
1 : 12-21 high card points Shows 4 plus Diamonds.
1 : 12-21 high card points Shows 4 plus Hearts.
1 : 12-21 high card points Shows 4 plus Spades.
1 NT: 15-17 high card points Shows balanced shape.
2 : 22+ high card points Shows any shape and is one-round forcing.
2 : 8-11 high card points Shows 6 Diamonds.
2 : 8-11 high card points Shows 6 Hearts.
2 : 8-11 high card points Shows 6 Spades.
2NT: 20-21 high card points Shows balanced shape.


Note: For the interested bridge student Mr. Jim Loy has presented a summary of the Jacoby Modern system, which the student can review at this link, and which is dated 1996. This summary has only been preserved and archived on this site also in .pdf file format for future reference. We suggest that the interested student purchase the book published by Mr. Oswald Jacoby with his son Mr. James Jacoby for additional explanations and clarifications.



If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.