The Jacoby 2NT convention is an artificial, game-forcing response to a 1 or 1 opening bid.
The
2NT response shows 4+ trump support with 13+ points. The bid asks partner to describe her hand
further so that slam prospects can be judged accordingly.
In his 1970 book "Win at Bridge with Jacoby Modern", Oswald Jacoby listed a couple caveats for
bidding 2NT:1
Responder's 13+ points should include at least 11 HCP.
Strong 3-card support is acceptable, e.g. 2 of the top 3 trump honors
Jacoby 2NT is intended for 5-card major systems that employ limit raises for game invitations. Thus,
it fills the need for a game-forcing raise with unlimited strength. The convention doesn't come up
often, but is precious in its role.
In ACBL games, Jacoby 2NT is alertable.
Opener's Rebids
After the auction begins 1 / : 2NT, opener's rebids are as follows.
Opener's Meaning
Rebid
3 Singleton or void in clubs. Bidding 4 next would show a void.
3 Singleton or void in diamonds. Bidding 4 next would show a void.
3 If are trumps, then this rebid shows 16+ points with slam interest. It asks responder to describe
If are trumps, then this shows a singleton or void in hearts. Bidding 4 next would show a void
3 If are trumps, then this rebid shows 16+ points with slam interest. It asks responder to describe
If are trumps, then this shows a singleton or void in spades. Bidding 4 next would show a void
3NT 14-15 points, balanced. The point range varies by partnership agreement. Oswald Jacoby original
required "a trifle" more than a minimum.
4 5+ clubs.
4 5+ diamonds.
4 If are trumps, then this rebid shows a minimum balanced hand (12-14 points). It is a signoff.
If are trumps, then this shows 5+ hearts.
4 If are trumps, then this rebid shows a minimum balanced hand (12-14 points). It is a signoff.
The Priority of Opener's Rebids
Many of the above bids overlap. For example, opener might have 5-5-2-1 shape with 12 points.
Should she bid the side suit, show the singleton, or simply jump to game?
Generally speaking, the priority of responses are:
1. Showing a 5-card side suit.
2. Showing a singleton or void.
3. Bidding 3NT with a balanced 14-15 points.
4. Jumping to 4 of the agreed major with 12-14 points.
5. Bidding 3 of the agreed major with 16+ points and no other suitable call.
Opener has a little latitude, some of which is described in the next section.
When Opener Bids a Side Suit
When opener bids a 5-card side suit, how good should it be? Modern bridge literature generally
advocates some sort of standard. As the thinking goes, you probably don't want to bid something like
Jxxxx and leave responder guessing how to value Kxx.
However, expert opinions differ on minimum suit quality. The following are two philosophies.
David Lindop recommends "two of the top three or three of the top five honors." With less, he
advises bidding the singleton or void instead.2 This can work nicely in a scenario like
AKxxx opposite Qxx
When opener promises two of the top three honors, responder sees that the suit will run, and takes
steps toward bidding a magic slam. However, these strong holdings are uncommon; you could wait
a long time to benefit from this agreement.
As a more relaxed standard, Larry Cohen recommends a "decent" second suit with the "ace or
king".3 Presumably he too would bid his short suit otherwise.
Cohen's approach might be more practical. Promising one top honor still helps partner to judge the
fit of the hands, but it allows opener to show side suits more frequently than the former approach.
Responder's Rebids
After any 3-level rebid by opener, responder can bid any suit (besides the agreed trump suit) to
show a first-round control - i.e. an ace or void.
After ANY rebid by opener, 4NT is Blackwood (or Roman Key Card Blackwood).
2NT by a Passed Hand
Jacoby 2NT is off when responder originally passed. In that situation, 2NT is natural and non-forcing,
showing a balanced 11-12 HCP.
Example
Opener Responder
AK843 QJ52
A932 KQ
J A862
T98 Q53
Opener Responder
1 (1) 2NT (2)
3 (3) 4 (4)
4 (5) 4 (6)
Pass (7)
1. 12+ points and 5+ spades
2. Jacoby 2NT showing 13+ points and 4+ spades - game forcing!
3. A diamond singleton or void
4. First-round diamond control
5. First-round heart control
6. A willingness to stop in game, implying concern about the club suit. With a club control,
responder would have bid 4 instead of 4 .
7. Opener does not have anything extra to show, and is satisfied with game.
In Competition
Jacoby 2NT is off when the opponents intervene over 1 / . In that situation, a 2NT bid by
responder is commonly used as a limit raise (the Jordan 2NT convention).
