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Limited Bidding: Reengineering Jacoby 2NT
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My last post discussed splinter bids and analyzed why they work so much better than the generic forcing raise they replaced. I identified three principles which explain why splinter bids work well:

  • Limit your values to allow partner to judge whether the partnership is in the slam zone. 
  • Describe your shape to allow partner to determine whether his high cards are working. 
  • Get to game without giving information to the defense when the partnership has only game values.

Let's apply these three principles in overhauling another popular convention: Jacoby 2NT



Jacoby 2NT
Jacoby 2NT is the modern version of the old 3M forcing major suit raise. Like the old forcing raise, it is wide-ranging in values shown and covers a wide range of shapes. Responder normally has a balanced pattern but he may hold a singleton if he is too strong for a direct splinter.

After 1M  --  2NT the partnership has found a 9-card trump fit and created a force to game, but neither hand is limited and neither has provided useful information about side suit shape. Therefore, the partnership rarely can tell immediately if it is in the slam zone. Fortunately, the auction is still low so there is time for limiting hands, showing shape, and picking a captain. But which partner should be showing shape? And which should be making limit bids?

As a general rule, when one hand is balanced and the other unbalanced, the unbalanced hand should show its shape and the balanced hand should be captain. The balanced hand is much better placed to understand what proportion of the partnership's assets will contribute to taking tricks. This is called, "The Balanced Hand Principle."

Since the J2N bidder is normally balanced and opener is often unbalanced, it makes sense for opener to show shortness and for responder to become captain. However, if the J2N bidder has a singleton, he should have a way to describe his own shortness instead and give captaincy to the opener.

Standard J2N Responses

Opener's standard responses to J2N are:

  • New suits at the 3-level show shortness
  • 3M shows no shortness and significant extras (17+)
  • 3NT shows no shortness and moderate extras (14-16)
  • New suits at the 4-level show a second suit with 2- of the top 3 honors
  • 4M shows a minimum with no shortness

Problems with Standard J2N Responses

  1. There is no provision for responder to show shortness; responder's continuations after 2NT are defined simply as "cuebids". 
  2. When responder has a big hand, opener's jump to 4M may force responder to explore slam at an uncomfortably high level. Few things are more irritating than making a nice low 2NT response, planning to cuebid slowly up to or beyond 4M, only to hear partner sabotage your planned auction by jumping to 4M.
  3. Although opener can describe his shortness, neither opener nor responder has a clear way to limit their hand afterwards.

As responder can you tell if the partnership is in the slam zone? 

South
AQxx
Kxx
Qxxx
Qx
W
N
E
S
1
P
2NT
P
3
P
?

While your cards seem to be working fairly well, you can't tell whether partner holds:

North
Kxxxx
Axx
x
AKJx
South
AQxx
Kxx
Qxxx
Qx
W
N
E
S
1
P
2NT
P
3
P
?

North
KJxxx
QJx
x
KJxx
South
AQxx
Kxx
Qxxx
Qx
W
N
E
S
1
P
2NT
P
3
P
?

At the moment we have two unlimited hands floundering upwards hoping to sort things out. Under those conditions, slam auctions will sometimes be ambiguous, good slam will be missed, bad ones will be bid, and arguments about "judgment" are sure to ensue.
 
One solution is to adopt Serious 3NT, as described in my earlier articles on 2/1 bidding.  Using Serious 3NT, you have an extra tool to describe hands with moderate slam interest meaning that 4-level cuebids can promise really big hands. This is certainly an improvement over nothing, but we can do better if we improve our J2N responses slightly. The scheme below is one I came up with. I don't claim it is the best, nor is it unique. Many or most top partnerships have adopted revised J2N responses of one type or another.
 


Revised J2N Responses

W
N
E
S
1
P
2NT
P
?

3     =   Any minimum (approximately 11-13 unbalanced or 11-14 balanced)
3     =   Extras (14+ HCP) with a singleton somewhere
3     =   Extras (14+ HCP) with a void somewhere
3     =   Moderate extras (14-16) and no singleton (5-4-2-2, 6-3-2-2, 5-3-3-2, 7-2-2-2)
3NT   =    Significant extras (17-19 including adjustments for distribution) and no singleton
4X     =    A 5-card second suit with 2 of top 3 honors

The most important call is the 3 bid. This low level call is opener's first move on all minimum hands. Any other call by opener promises at least moderate extras. Opener will simplify many auctions by immediately identifying the minimum hands. 

 

Auction 1--Opener has a minimum

When opener shows a minimum, there are two possibilities:

  • Responder has a minimum too
    Slam is unlikely so responder can immediately place the contract in game.
     
  • Responder has extras
    Slam is still possible so more exploration is needed. Responder now has a second decision to make, should he describe his own hand or should he ask opener to describe his? In general, when responder has a singleton, he should describe. When responder is balanced, he should ask.

South
AQxx
KJx
Qx
xxxx
W
N
E
S
1
P
2NT
P
3
P
4
P
P
P

Holding a 12-count himself, South can tell immediately that slam is unlikely whatever opener holds so he jumps to 4M. This has two important benefits:

  • A slam misunderstanding is instantly avoided
  • Opponents must defend 4 when both partners are minimum, without information about opener's side suit distribution. 
 
South
AQxx
xx
AQxx
KQx
W
N
E
S
1
P
2NT
P
3
P
3
P
?

Responder is balanced with extras, so he asks for opener's side suit shape. The responses are

1   --   2NT
3   --   3
3          =    no shortness
3          =    lowest singleton (clubs)
3NT         =    middle singleton (diamonds)
4          =    highest singleton (hearts or spades)

This is almost the same scheme we used over the mini-splinter. The only difference is the first step response (3) which shows no shortness. The acronym to remember is NLMH which stands for none-lowest-middle-highest, since the first step response shows shows no singleton, the second step shows the lowest singleton, etc.

 

South
AQxx
KJxx
AQxx
x
W
N
E
S
1
P
2NT
P
3
P
4
P
?
 
Responder has a singleton club and is too strong for a direct splinter (15-17 HCP). Rather than ask about opener's he hand, he should describe his own shape. Opener should be the captain of this auction.

 

Auction 2 and 3--Opener has extras and shortness

1M   --  2NT
3 (singleton somewhere)  --   3 (where?)
3            =    lowest singleton (clubs)
3NT           =    middle singleton (diamonds)
4            =    highest singleton (hearts or spades)

 

1M   --  2NT
3  (void somewhere) --   3 (where?)
3NT           =    lowest void (clubs)
4            =    middle void (diamonds)
4            =    highest void (hearts or spades)

Note that the responses to the asking bid are the same as over a mini-splinter:
1st step     = lowest shortness
2nd step   = middle shortness, etc.

 

Auction 4 and 5--Opener has extras and is balanced

1M  --  2NT
3 (no shortness 14-16)  --  ?

 

1M    --  2NT
3NT  (no shortness 17-19) --  ?

Opener is narrowly limited. The J2N bidder is captain and may cuebid, bid RKC, or signoff in game.

In summary then, our new responses:

  • Allow opener to limit his hand
  • Allow opener to describe his shape
  • When responder holds a singleton, allow responder to describe his shape and limit his hand
  • Allow responder to bid game without revealing opener's shape when both hands are minimum

The new responses exploit limit bidding to improve our slam auctions by making it easier to tell when to cuebid and when to sign off in game and our game auctions by allowing us to jump to game uninformatively when we are not in the slam zone.

Removing a Fly From Our Ointment

Suppose you hear your opponents use Jacoby 2NT:

West
xxx
xx
KQ109x
xxx
W
N
E
S
1
P
2NT
?

What will you bid? Expert players have realized that a 3 call is a safe way to get the best lead against 4. The opponents have a vul game and a 9+ card fit, it will be almost impossible to double your audacious bid. They have to beat you three or four to exceed their game bonus and how likely is that when they have 9 spades? Further, they can't know just how aggressive you have been. An overcaller might make the same call on a more distributional hand. To an aggressive expert player, a J2N bid is like waving a red flag, saying "Bid on air! Get your lead, disrupt me please!"

Can we modify our methods to prevent this impertinence? The answer is yes, although the solution is counter-intuitive. If we allow the 2NT call on weaker hands, it is no longer safe for our opponents to interfere on junk! When the opening side is guaranteed to have game going for a number is a small risk. But when the opening bidders might only have a partscore, a number is a serious risk. Further, when the opening side may be weaker, then the defenders may be stronger. In turn, that means the defenders must have a care for constructive bidding. If they overcall on junk, how can they show a hand like: x, Ax, AKT9xx, JTxx?

The solution is to convert 2NT to showing a limit raise or better. The responses I proposed earlier are well-suited for handling 2NT as a limit raise or better.

 

Showing a limit raise after J2N
1M         --    2NT (limit raise +)
3         --   ?

3 = shape ask. Responder has extras and a balanced hand.

3M  =  A limit raise. This sequence is not forcing, but opener can continue if he is shapely.

Other calls = Responder has shortness in the bid suit and is too strong for a direct splinter.

4M = To play. Responder holds a minimum game force.

 

1M         --  2NT
3D/3H    --  ?

Whenever opener's response shows extras, a game force is established. However, responder can show a limit raise to warn opener of his relative weakness.  Responder rebids:

First step = asking for opener's shortness. Implying an opening bid.

3NT = A limit raise.
Opener is now captain.3NT leaves the auction low enough that opener can explore for slam if he likes.

 

1M         --  2NT
3S/3NT   --  ?
4M = limit raise or better not interested in slam.

Changing J2N to showing a limit raise or better has a nice side effect: it frees a direct 3M for another use. I like to use 3M as a sound preemptive raise, showing something like:

South
KJxx
x
J10xx
xxxx
W
N
E
S
1
P
3
P
P
P

 

Conclusion

Limit bidding solves many mysteries that plague intermediate players. Reduce the number of unlimited groping auctions, and both your slam and game auctions will get much better. Next week, more talk about the slam zone and how to know when to try for slam.

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