Bidding and conventions
Jacoby 2NT
Jacoby 2NT is a 2NT response to partner's major-suit opening that shows four-card support and at least game values. Because it forces to game at once, the partnership can use the three level to find out whether there is a slam.
The problem it solves
Partner opens 1♠ and you hold 15 points with four spades. You know you're playing at least game in spades. The question is whether the two hands fit well enough for twelve tricks.
Without a convention, none of the natural bids works well. Bidding 4♠ shows the fit but leaves no room to look for slam. Jumping to 3♠ is invitational, which understates your hand. A new suit describes a side suit when what you want to show is the fit.
Jacoby 2NT agrees the suit and forces to game in one bid, leaving the three level free to explore slam.
In exchange you give up 2NT as a natural response, which you rarely want with four-card support for a major, and gain several rounds of description below game.
What you need to bid it
- Four or more cards in partner's major. Not three.
- 13+ points, enough to force to game.
- No singleton or void in most partnerships' style. With real shortage, a splinter bid describes the hand better.
- You must not be a passed hand. A passed hand can't hold 12 points, so 2NT reverts to its natural meaning, or to Drury, if you play it.
15 points, four-card support, no shortage. Game is certain; slam depends on partner.
Also 13+ with four spades, but the singleton heart is the thing to show. Splinter with 4♥ instead.
Opener's rebids
This is a common schedule, but not the only one, so agree it with your partner.
- Three of a new suit: a singleton or void in that suit. This is the first priority, ahead of showing strength, because shortage opposite wasted honours often decides whether a slam makes.
- 3NT: a strong balanced hand, roughly 15–17, with no shortage anywhere.
- Four of a new suit: a good five-card side suit, usually with extra values.
- Three of the agreed major: extra values, no shortage, slam interest.
- Four of the agreed major: a minimum opening with nothing else to say. This is the signoff, and responder should respect it.
A hand where it works
14 points. A minimum in high cards, but a singleton diamond and 5-4 shape.
15 points, four-card support, three small diamonds.
| West | North | East | South |
|---|---|---|---|
| 1♠ | |||
| Pass | 2NT | Pass | 3♦ |
| Pass | 4NT | Pass | 5♥ |
| Pass | 6♠ | Pass | Pass |
| Pass |
Responder's three small diamonds mean no high cards are wasted opposite opener's singleton, and there are twelve tricks.
Had responder held ♦ K Q x instead, the same 15 points would be worth far less and the auction should stop in game. Point count alone doesn't show the difference; opener's shortage bid does.
Agree the details before you play it
Partnerships differ on each of these, so agree them before you play:
- Whether 3NT shows a strong balanced hand or a minimum one. Partnerships play both.
- Whether three of a new suit shows shortage or a real second suit.
- Whether the convention applies after an opponent's overcall. It's common to play that it doesn't.
- Whether responder may hold a singleton.
If you agree only one thing, agree what a new suit at the three level means.