This Week in Bridge
(407) Jacoby 2NT
© AIB Robert S. Todd
Level: 3 of 10 (1 of 6) robert@advinbridge.com
General
Finding a fit and showing this fit to partner is one of the most important parts of constructive bidding. When partner opens the bidding with a Major suit, showing that we have a large fit for their suit and a good hand is one of Responder’s most important bidding tools. When we have enough values to force to game after partner has opened the bidding and we have a big fit for their Major suit, we would like to have a way to show both pieces of information to partner immediately. This is done by using a special conventional bid, called Jacoby 2NT. Let’s see how this bidding tool works.
Jacoby 2NT Response
When partner opens the bidding with a 5-card Major suit and we have an opening hand of our own (12+ points) and also have 4+card support for partner’s Major suit, then we can use a conventional bid of 2NT* to show our hand.
1♥ 2NT* 4+card ♥, 12+ points, game forcing
1♠ 2NT* 4+card ♠, 12+ points, game forcing
This artificial raise of Opener’s Major suit allows our side to create a game forcing auction (knowing that we are going to at least 4-Major) and leaves space between 2NT and 4-Major for us to explore bidding a slam. This Jacoby 2NT bid is more effective than other options -- jumping to game (eating up all our side’s bidding space) or bidding a new suit at the 2-level (making a 2/1 Game Forcing bid) which shows our values but hides our large fit with partner.
Let’s see how we make use of this extra bidding space to explore slam after we show partner our 9+card Major suit fit and game forcing values.
Opener’s Rebids After Jacoby 2NT
After Responder bids Jacoby 2NT, Opener should describe their hand to Responder -- both strength and shape. We have an artificial structure for doing this along the way to 4-Major (or higher). Opener usually shows shortness at the 3-level - bidding a new suit at the 3-level shows a small singleton or void.
With no shortness to show (usually a balanced or semi-balanced hand) then Opener describes to Responder the strength of their hand – small, medium, or large.
Opener’s Rebid Traditional Meaning Modern Meaning
4-Major 12-14 points (small) 12-13 points
3NT 15-17 points (medium) 14-15 points or Min w/ Controls (AK, A)
3-Major 18+ points (large) 16+ points
Note: Additionally, it is not a good idea to show shortness with a singleton Ace or King – this will cause partner to improperly evaluate their hand. Instead, it is best to show these hands as balanced – bidding 4M, 3NT, or 3M with a singleton Ace or King.
Notice we have not used new suits at the 4-level to describe our hand. These bids are traditionally used to show a “good 5+card side suit” (at least 5-5 shape) – a source of tricks for slam. For most partnerships this second suit shows 2/3 top honors, allowing Responder to bid aggressively towards slam with the 3rd fitting honor. With a 5-5 hand that has a weaker side suit, Opener simply shows their shortness at the 3-level (since all 5-5 hands must also have a singleton or void.)
Note: For more information on how to think about these hands, how to try for slam using Jacoby 2NT, and follow-ups in these type of auctions, see TWiB #21 on Hand Evaluation.
Details of Modern Jacoby 2NT Auctions after a 1♠ Opening
1♠ 2NT*
__?
3♣* S/V in ♣, unlimited values
3♦* S/V in ♦, unlimited values
3♥* S/V in ♥, unlimited values
3♠ Large hand, 16+ points, usually no shortness
3NT Medium hand, 14-15 points or a “control rich” minimum
4♣ Good 5-card ♣ suit (usually 2/3 top honors), unlimited values
4♦ Good 5-card ♦ suit (usually 2/3 top honors), unlimited values
4♥ Good 5-card ♥ suit (usually 2/3 top honors), unlimited values
4♠ Small hand, 12-13 points (Fast Arrival)
And similar for 1♥ - 2NT*.
Note: At any point in a game forcing Jacoby 2NT auction, a jump to game (4-Major) is a “Fast Arrival” bid – saying that we have less interest in slam based on the information we have received.
What to Do with Hands that Used to Bid 2NT Naturally
Whenever we add a new convention to our bidding system, we give up a natural bid. it is important to figure out how we should describe the hands that would have used this natural bid. In this case, how do we show a balanced invitational hand (good 10 to bad 12 points) without a fit for Opener’s primary suit – a hand that would have bid a natural and invitational 2NT?
If Responder holds this hand, then they now simply bid 1NT (instead of 2NT). If you play 2/1 Game Forcing then we are already familiar with this bid: 1NT Semi-Forcing (or 1NT Forcing), which shows 6 to a bad 12 points, instead of 6 to a bad 10 points.
Note: Even if we do not play 2/1 Game Forcing, we can simply show an invitational hand with no fit for Opener’s suit by bidding a new suit at the 2-level (showing 10+ points) and then rebidding 2NT on the second round of the bidding, limiting our hand. But we can also start with 1NT in a similar way.
Conclusion
Jacoby 2NT is an excellent addition to natural bidding and is one of the first conventional bids normally adopted, giving our side a tool to explore for a Major suit slam when Responder has both an opening hand and a large Major suit fit. When you have a large fit for Opener’s 5-card Major suit, use this tool to let partner know that you are going to at least game in the Major and set up an auction that uses the extra space to explore for slam without going past game. This convention is a key part of modern slam bidding.