Most partnerships use 1M-2M as a simple raise or a constructive raise. 1M-3M is typically used as a 4-card invitational raise. A 3-card invitational raise is typically shown with an initial 1NT response followed by a jump raise. A game forcing raise with 3-card support begins with a 2/1 Game Force followed by a raise. Most partnerships use a conventional Jacoby 2NT response to a major suit opening to show a game forcing raise with 4-card or better support. Pairs playing Splinter Bids will typically use Jacoby 2NT for a balanced or semi-balanced game forcing raise. If responder is too strong to make a splinter bid, responder uses Jacoby 2NT even if they have a singleton or void in a side suit.
The Traditional Jacoby 2NT Structure:
See Karen Walker’s “Jacoby 2NT -- Forcing Major-Suit Raise” article for a good discussion of the traditional continuations after a Jacoby 2NT game forcing raise.
The Jacoby 2NT game forcing raise is typically off in competition, and off by a passed hand. After an overcall, it is common to use a cue bid to show an invitational or better raise. Over a takeout double, partnerships playing Jordan will use 2NT as a conventional raise showing invitational or better values. Passed hands would be well advised to use some form of Drury to show an invitational raise.
Problems with the Traditional Structure:
There are several problems with the traditional Jacoby 2NT continuations.
1. The Fast Arrival jump to 4M (1M-2NT-4M) preempts partner’s slam exploration. In his blog, Justin Lall recommends against using Fast Arrival opposite an unlimited hand. When responder has a big hand, the jump to 4M can force a guess as whether a slam is available. Responder does not have room to determine if opener’s values are working well with their hand. The Fast Arrival 4M rebid can lead to missed slams, and to risky 5-level contracts.
2. The shortness showing 3-level responses provide useful information for the defense. If opener has a minimum hand and responder has no slam interest, describing opener’s distribution is helpful only to the defenders.
3. 5-4-2-2 and 6-3-2-2 hands are not handled well in the commonly used Jacoby 2NT structure. Pinpointing opener’s doubletons can be very useful for slam bidding.
Jacoby 2NT Upgrades:
To avoid these problems, many expert partnerships have adopted Jacoby 2NT structures which hide opener’s shape with a minimum hand, and allow more precise slam exploration. The key modification is the use of a cheap bid to show a minimum opener. If responder has slam interest opposite a minimum opener, there is room to explore the potential for slam. Otherwise, responder simply places the contract in game; and opener’s distribution is hidden from the defense.
The articles below provide expert advice to improve your bidding after a Jacoby 2NT response. If the traditional Jacoby 2NT responses were natural or intuitive, one might be hesitant to replace them. Since the traditional responses are artificial, advancing partnerships may wish to discuss incorporating some of the expert recommendations into their agreements.
- In his "Limited Bidding: Reengineering Jacoby 2NT" article, Andrew Gumperz recommends using an artificial 3♣ bid to show a minimum opener. If opener shows a minimum hand, responder can ask about opener’s shape if interested in slam. Otherwise responder places the contract at game, hiding opener’s distribution. An immediate 3♦ or 3♥ response by opener shows extra values and unspecified shortness. 3♦ shows an unspecified singleton. 3♥ shows an unspecified void. Responder can then ask the location of opener’s shortness. Later in the article, Andrew provides an optional recommendation to include 4-card invitational raises in the Jacoby 2NT response. This has the advantage of allowing a 1M-3M to be used as a preemptive raise or a mixed raise. Including invitational raises in the Jacoby 2NT makes it more risky for the opponents to interfere in your Jacoby 2NT auctions.
- Those willing to take on a bit more complexity can benefit from Larry Cohen’s "Modified Jacoby 2NT (for Advanced-Expert Level)" article. Cohen’s structure uses an artificial 3♣ response to show a minimum opener. So opener’s distribution is hidden when not in the slam zone; and the preemptive 4M Fast Arrival rebid is avoided. The structure allows opener to show hands with singletons, hands with voids, balanced hands, and semi-balanced hands.
As Andrew Gumperz describes in his “Evaluating for Slam 5: Jacoby 2NT Auctions” article, fitting doubletons in opener’s hand can make slam possible with fewer HCP. So Cohen’s structure to locate opener’s doubletons when opener holds a semi-balanced hand (i.e. 5-4-2-2, 6-3-2-2, 7-3-2-2), position responder to use the partnership’s the Short Suit Total to assess slam chances.
- In his “Wilson 2NT” article, Kevin Wilson recommends including 4-card invitational raises and powerful Splinter bids into the 2NT game forcing response. Kevin’s structure is similar in many ways to Larry Cohen’s recommendations, but adds provisions for the invitational raises and big Splinter hands.
When you have a 9-card or better major suit fit, it is rarely right to play 3NT. So many expert partnerships have applied a conventional meaning to a 3NT bid in a Jacoby 2NT auction. The 3NT bid is typically used as a switch to show (or deny) extra values in the context of the previous bidding. Using the 3NT bid as a non-serious slam try, showing willingness to cooperate if partner is interested in slam, makes it easy to differentiate a hand with strong slam interest from a hand which is willing to cooperate with a slam try (the Serious 3NT convention provides the same benefit but uses an artificial 3NT bid to show strong slam interest). If playing the traditional version of Jacoby 2NT, it is vital to play Serious 3NT (or Non-Serious 3NT) is essential. When the auction begins 1M-2NT-3m, opener has shows a 5-card major and shortness in a minor and responder has shown a game forcing raise. Both hands are unlimited, but neither has guaranteed extra values. To aid slam bidding, it is vital to have a way to show (or deny) serious slam interest. See Andrew Gumperz's "Evaluating for Slam 6--More Tips about Jacoby 2NT" article for tips on slam bidding after a Jacoby 2NT game forcing raise.
It is always nice when the opponents remain silent while you and your partner assess slam chances. Some of your opponents may not be so cooperative. A lead directing overcall can pay big dividends. Sometimes the opponents will preempt your Jacoby 2NT auctions. Billy Miller shares advice on handling Jacoby 2NT interference in his "The Coolest Gizmos and Gadgets" column. Billy recommends a structure enabling a partnership to quickly determine if they have two quick losers in the opponent's suit. The structure makes it easy for either partner to simultaneously describe their hand and show a control in the opponent's suit.