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Jumping Jacoby... wow.. who needs this wacky thing....

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Posted 2004-November-17, 19:39

Jumping Jacoby Auctions:

Over a natural 1NT opening bid, a jump to 3 Diamonds or 3 Hearts by responder promises at least game going value and 5 or more cards in the next higher suit. Also, Opener will never have as many as four or more cards in the second major (I have a double major stayman conventions if anyone is interesing). Since this is game force, opener must bid again, but is not required to complete the transfer. The meaning of Opener’s Rebids after 1NT-3 (similar rules after spade transfer):
  • 4 - Shows a fit, but only 0-1 Key card in support of the major (out of six -KQ of trumps and side suit Aces. This bid can also be made on support hands with 2 Key Cards which include 1) a minimum count, and 2) a total of 4 side suit low honors (Queens and jacks).
  • 3NT - Four Controls, no fit
  • 3 - 0-3 controls. With Fit, will be 2-3 Controls
  • 4NT - Five Controls (Can not hold six!) with or without fit. Opener obviously has little else playing 15-17 or 16-18 HCP 1NT opening bids.
  • 3, 4, 4 = Shows four key cards in support of the major, and is cue-bidding the cheapest ACE. (for instance, 4 shows AKQ and A, and no minor suit ace). *IF you open 1NT on 5-4 hands, you could play this as good fit (strong 3 card or 4 card support) and a five card side suit with two of the top three honors. Since I tend not to have this hand, I don’t play that way.

If after opener’s first response, two key cards are missing, and responder is looking at the major suit queen in his own hand, the slam is pretty much out of the question *unless* responder has a void. It is true you can make the slam on some hands without a void holding four key cards counting the trump queen, but the these require at a the missing key card to be the trump king, and the finesse to work, and no ugly surprises (bad trump splits or early defensive ruffs). So they are 50% slams at the very best.

On these auctions, responder will know all about the number of controls. For responder to make a grand slam try by asking about trumps after a fit has been established, clearly indicates he wants to bid the slam only when the trump queen is missing. For this reason, some of the normal meanings to a leap to 5NT or a bid of one under the agreed upon trump suit at the six level have unusual or “reversed” meanings. I call these “Reverse GSF” and “Reverse Josephine.”

Rebids after Completing the Transfer: The Most Common Auction:
1NT     3                     1NT     3
3     ?                     3     ?

Responder’s Rebids show:
  • 3NT = Five card major, game value. Little to no slam interest.
  • 4-of-the major = 6 loser with (with 7 loser, use Texas instead of jumping jacoby).
  • 3 (over ) = Transfer for exclusion bid. Opener rebids 3NT (responder can not have two major suits) - responder then shows short suit
  • 4 (over 3) = Exclusion bid, shows 6+ spades, and singleton or void in ’s (no major two suiter)
  • 4,4 = second suit. Generally promises six - five or a really good major and four card minor. This bid always shows interest in slam.
  • 4NT = five card major, 5-3-3-2 distribution, willing to be in slam opposite a major suit fit.

When responder shows a two suiter (in this case, a major and a minor, with a 4C or 4D rebid), a cover card concept is used to assess the slam possibility. Over 4C or 4D, opener must assess his support for the major and possible cover cards, where the AKQ of both responder suits, and the side Aces are all worth 1 cover card each; a side suit King is treated as a ½ a cover card, and a side suit AQ is treated as 1½ cover cards, and a side suit AK is treated as two cover cards.

Opener’s responsibility over four of a minor is to show his support or lack of support for the major and his total cover cards. Without major support opener rebids 4NT with 4-or-less cover cards, and 5minor with 4½ or more cover cards. With support, opener rebids 4 of the major with 3 cover cards or less. All other bids (not 4NT, 4-of-the major, or 5-of the minor) show a major suit fit and more than 3 cover cards (EXCEPTION - If opener can bid below four of the major, it shows three cover cards PLUS king in bid suit). Thus, opener’s rebids are: a new suit at the four level shows 3 cover cards plus the king in the bid suit if below the agreed major. New non-jump suit above the agreed major shows 4 cover cards plus the king in the bid suit. A jump to five of the major shows four cover cards with no side suit king, 5NT shows five cover cards and a possible side suit king.

On some hands, responder will two ways to show this hand, as a one suited hand using exclusion bids (showing his short suit) or as a two suiter. When responder shows a two suiter, without support for the major, opener has three options: 1)bid 4NT, 2) bid five of the minor, or 3) since this auction is usually based upon a six card suit, show support with doubleton honor support when lacking good support for the minor.

The 4NT bid shows at most 4 Cover cards (AKQ of both suits shown by responder and two side aces), 5 of minor shows 4½ + cover cards. All bids except 4NT and show major support (hence 2-3 Key Cards...remember, with a heart fit, opener will generally have 3 Key Cards (for the major) or 2 key cards and better than a minimum). The options are:
  • New suit below 4-of-the-agreed Major = 3 Cover cards and king in bid suit.
  • 4-of-the-agreed Major = Less than 4 Cover cards (obvious inference available if opener could have bid a new suit below 4-of-the major).
  • New suit between 4 and 5 of the major = 4 Key cards plus king in bid suit.
  • Five of the major = 4 Key cards, no king in the other two suits.
  • 5NT = Five Cover Cards (5S over heart suit shows 5 cover cards and king of spades!)

This frees up your 2 level responses to 1NT to be something else. The tradeoff when you just have game hand versus regular jacoby is nothing.. their auciton would be 1N-2H-2S-3NT or 1N-2H-2S-4S.. while with jumping jacoby, the auctino would be 1N-3H-3S-3NT or 1N-3H-3S-4S. When I play jumping jacoby, I play invitational 2, descrbied elsewhere in these forums.


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Posted 2004-November-18, 12:49

I was asked why bother with jumping jacoby, when you can do all this at the two level without the memorization. Good point. But the reason why is this, since it is game forcing, the balanced hand (1NT opener) can describe to his distibution partner fitting key cards and fitting cover cards. Just what responder needs for some magic fit slams. Consider this hand (only one i ahve on computer.. i can dig some out of some notebooks if anyone is really instrested.....

IMP-20                  Dlr: South 
Board 32886 S 6         Vul: Both
            H QJT852    
            D AK54        
S KQ982     C 73        S AT        
H 43                    H 97        
D T982                  D QJ6       
C 96        S J7543     C QT8542    
            H AK6       
            D 73        
            C AKJ       

West     North    East     South    
Pass     3D       Pass     3H       
Pass     3S       Pass     3NT      
Pass     4H       Pass     6H       
Pass     Pass     Pass     

 1. 3D = game force jumping jacoby
 2. 3H = no more than 3 key cards
 3. 3S = transfer for exclusion bid
 4. 3N = complete transfer
 5. 4H = short spade
 6. 6H = four and half working cover cards, plus ruffing value

Opener could have cue-bid 5C to show 3 keycards, and the king of clubs (at least four covercards). 

Opening lead: DT    Result: Made 6
Score: 1430         Points: 12.07 

  # Contr   Ld  Decl     Tr  Score   Pts
  1 6H    S DT  xxxxx     12  1430  12.07          
  2 6H    N SA  xxxxxxx   12  1430  12.07          
  3 4H    N ST  xxxxxxx   13   710  -0.47          
  4 4H    S SK  xxxxxxx   12   680  -1.53          
  5 4H    N C2  xxxxxxx   12   680  -1.53          
  6 4H    N C2  xxxxx     12   680  -1.53          
  7 4H    N DQ  xxxxxxx   12   680  -1.53          
  8 4H    N DQ  xxxxxxx   12   680  -1.53          
  9 4H    N H9  xxxxxxxx  12   680  -1.53          
 10 4H    N H7  xxxxxxx   12   680  -1.53          
 11 4H    N SA  xxxxxxx   12   680  -1.53          
 12 5H    N C5  xxxxxx    12   680  -1.53          
 13 4H    N SA  xxxxxxxxx 11   650  -2.47          
 14 4H    N H7  xxxxxx    11   650  -2.47          
 15 4H    N C5  xxxxxxx   11   650  -2.47          
 16 4H    S D8  xxxxxxxx  11   650  -2.47          


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