No.1809 | 上へ | 前へ | 次へ
Subject: [BR] OKbridge Two over One
From: Satoshi Kuroyanagi 
Date: Thu, 08 Apr 1999 12:56:36 +0900 (JST)

畔柳です。
OKbridge 2/1 のコンベンションカードとサマリーです。

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System         simple 2/1 GF Always (by unpassed hand) except in comp
NT             15-17,Jxf,Txf,Leb,sys on over x,2S=mss or correct to 3d with
               diam bust, 2N->3C cl signoff or bid stiff in 4-4-4-1 next
               2N=20-21,Jxf,Txf,3S=MSS,Leb,sys on /x 3N=gmbl no otsde A or K
Majors         5cm, J2N(4X=2nd suit),1N=1 rd frce,rev drury,pjs in comp only,
               3N=balanced 16-17 HCP (4-3-3-3 or 4-4-3-2)
Minors         3+(usually 4 diam), inverted (force to 2nt or 3min)off only
               over x,2N=11-12,3N=13-15,bypass 1D unless GF strength
Strong         2C - 2D wait, cheapest 3 level is 2nd neg
Weak           5-11(wider 3rd, stronger 4th),2NT-feature,RONF
Overcalls      8-16,new suit nf tends to deny good supp, Q=1rd frce, Qthen new
               suit forcing, weak raises if next opp doubles
NT-Over        15-18,System on-incl Lebenshol if next opp bids
Doubles        Neg-3S, Resp-3S, Support x and xx ->2H
Vs.Doubles     Jordan 2N (maj and min), raises are weak
               if partner opener-new frce 1 level only,xx implies no fit 10+
Preempts       standard type (gen rule of 2 and 3), new suits forcing
Vs.Preempts    X=takeout, Lebenshol/weak 2 all seats
Cuebids        Michaels over maj or min (2N asks minor), nat over artificial
Slam-Bids      0314 RKC(last bid suit unless only 1 fit established)
Suit-leads     4th best, Xxx, Akx(x)A
NT-leads       4th best,Xxx,A asks honor-count if none, K asks attitide
Carding        standard signals
Misc           4SF(GF),NMF; capp/nt,over strong 1C or 2C X=maj, NT=minors

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THE OKBRIDGE TWO-OVER-ONE SUMMARY

Copyright OKbridge 1997
All Rights Reserved

     This description of the OKbridge 2 over 1 system assumes that
you are already familiar with the Standard American Yellow Card.
If not, you can request a complete description of the Standard
American Yellow Card by sending email to help@okbridge.com .  The
OKbridge 2 over 1 system is recommended for intermediate players
and up.

CONTENTS

CHAPTER 1..................................THE 2/1 STRUCTURE
CHAPTER 2..................................MAJOR-SUIT CONVENTIONS
CHAPTER 3..................................1NT CONVENTIONS
CHAPTER 4..................................DOUBLES
CHAPTER 5..................................MISCELLANEOUS


CHAPTER 1- THE 2/1 STRUCTURE

There are lots of variations to 2/1, and the OKbridge card should
not be considered a universal standard.  In all 2/1 systems,
however, the general principle is the same- any new suit bid by
responder at the two-level is a game-force.  For example:

1S : 2C   Gameforcing.  Neither player can pass until a game of
          some sort is bid.  In the OKbridge system, there are no
          exceptions.
1N : 2N   Not a gameforce.  The two-level response must be in a
          new suit.
1S : 2S   Not a gameforce.  Again, the two-level response must be in
          a new suit.
1C : 2D   This is a strong jump shift and is, of course, gameforcing.


Opener's Rebids

Simple rebid            : The catchall bid, does not promise extra
                          strength
Jump rebid              : Solid 6-card suit or better
New suit at the 2-level : Natural, at least four cards, any strength
New suit at the 3-level : Splinter in support of responder
2NT                     : 12-14 balanced (no 3-card support)
3NT                     : 18-19 balanced (no 3-card support)
Single raise 		: At least 3-card support, any strength



2/1 and strong jump shifts are OFF in competition BETWEEN opener and
responder.  For example:

1S - 2C - 2D        2D shows 10+ points and is not gameforcing.  The            
                    interference is in front of responder.

1S - P  - 2C - 2D   2C is still gameforcing.  The interference is
                    behind responder.

1C - 1D - 2H        2H is a weak jump shift- 6 card suit, 0-6 points.
                    This is signoff bid and is, of course, NOT
                    gameforcing.

1C - P  - 2H - 3S   2H is a strong jump shift, great 5-card suit or
                    better, 17-19 points.  The partnership is still
                    in a gameforcing auction (unless they want to
                    defend 3S-X).


CHAPTER 2- MAJOR-SUIT CONVENTIONS

1NT FORCING

As a result of the 2/1 response being a game-force, responder will
often have a 10-12 point hand with which he would like to make a 2/1
bid but cannot; hence the 1NT Forcing convention.   The 1NT response
to 1H or 1S shows 6-12 and is a one-round force (since responder may
have 12 points).  Opener's rebids are as follows:

Any reverse             :  16+, natural, forcing
Simple rebid            :  12+, a good 6-card suit, nonforcing
Jump rebid              :  19+, natural, forcing
Jump shift in a new suit:  19+, natural, forcing
2NT                     :  18-19, balanced, nonforcing 

If opener's hand does not fit into these categories, he must bid his
longest side suit up the line if possible.  In each of the following
cases, opener has bid 1S and heard 1NT forcing:

KQJT9 KJT6 A3 54

Opener must rebid 2H.

KQJT9 KJT A63 54

Opener must rebid 2D. (alertable)

AQJT KJT98 Q6 54

Yuck.  Opener cannot reverse, so he must rebid 2C.  (alertable)

  
Responder's rebids are as follows.  First, the weak (6-9) rebids:

Pass                     : If opener has rebid 2m, responder should
                           try to have incredible 4-card support or
                           better, since the side may be playing in
                           a 4-2 fit.
New suit at the two-level: A five-card suit, signoff.
Two of opener's major    : Responder may only have two-card support.
New suit at the 3-level  : A very good 6-card suit, signoff.


Now, the strong (9-12) rebids:

2NT                     : Balanced, nonforcing
Three of opener's major : Invitational, normally 3-card support
Three of opener's minor : Natural, normally 5-card support
Jump to game            : Natural

Example hands.  Opener has opened 1H, responder has bid 1NT forcing,
and opener has rebid 2C:

K43 98 KJ43 J432  

Correct to 2H.  Don't pass!

K43 K98 AJ J9854

Invite with 3H.

T43 K8 QJ2 KQ876

Raise to 3C.

KJ3 A8 QJ32 T98

Bid 2NT.

6 A53 52 AQT876

You can try 4H now that a double-fit is apparent.


REVERSE DRURY

Based on the Drury convention invented by Douglas Drury, Reverse
Drury is an effective way of gauging the strength of partner's third
and fourth seat openers.  When partner opens 1H or 1S in third or
fourth seat, 2C by responder shows 10-12 points with at least three
trumps.  With a subminimum hand, opener bids 2M, telling responder
to pass.  With a normal opening bid, opener rebids 2D.  The natural
2C response is lost, but many players consider this a marginal
sacrifice.  Thus

Opener                                              Responder
KQJ4 K85 T98 762                                    A987 A93 K543 82
                             1S  :  2C!
                             2S! :  P 

And

Opener                                              Responder
QJT43 A8 KT63 A5                                    K987 K63 AJ95 32
                             1S  :  2C!
                             2D! :  3D
                             4S  :  P

Special Rebids by Opener:

1)  KQJ52 K987 A3 42
2)  KQ987 5 AJT32 A9
3)  AJ542 8 K9 AQT65

In each case opener has bid 1S and received a 2C response.
In 1), Opener bids 2H to show 4+ hearts in case there is a 4-4 heart
fit.  He does not guarantee opening strength.
In 2), Opener bids 2D, planning on rebidding 3D.  As he is committing
the partnership to the three-level, this does show a full opener.
In 3), Opener bids 3C to show his club suit.  Again, since he is
taking the bidding to the three-level, opener does promise a full
opener.


WEAK JUMP SHIFTS (IN COMPETITION ONLY)

A jump shift by responder in competition shows a 6-card suit and 0-6
points.  For example:

1C - 1D - ?

KQ7432 43 32 T98

Bid 2S.

Opener's rebids are:

Pass                     : On most hands, since responder only has
                           0-6 points.
2NT                      : Game try, forcing.  Responder must rebid
                           his suit to show a minimum.
Simple raise             : Purely preemptive.
Double raise of a minor  : Invitational.
Any new suit             : Natural, nonforcing. 


CHAPTER 3- 1NT CONVENTIONS


TEXAS TRANSFERS

Playing Texas Transfers, jump responses of 4D and 4H to a 1NT or 2NT
opening are respective transfers to 4H and 4S.  Texas transfers are
used when responder wants to be in game but has no interest in slam.
For example, bid 4D with K5 AT98543 52 52 in response to a 15-17 1NT.
Partner must bid 4H, which you pass.  The idea behind this convention
is similar to that behind Jacoby Transfers- it is better for partner
to be declarer rather than dummy since his high cards won't be exposed
to the defenders.  Using both transfer conventions, some players use
Jacoby as a slam invite and Texas as a signoff.

1NT  :  2H!
2S   :  4S

would suggest slam interest, while

1NT  :  4H!
4S

is a signoff.
How do Texas transfers work in competition?  In Modern Bridge
Conventions, Bill Root and Richard Pavlicek recommend playing them
through 3C, i.e.

1NT (3C) 4D!

is a transfer, while

1NT (3D) 4H

is natural.  A simpler (though perhaps less effective) method of
playing Texas Transfers would be to have them off completely in any
competition, a la Jacoby Transfers.


MINOR-SUIT STAYMAN

Minor Suit Stayman is just what its name implies: a device that allows
a partnership to look for a minor-suit fit after an opening bid of 1NT
or 2NT. Presupposing the use of Jacoby Transfers, the 2S response to
1NT is no longer needed and can be used to ask opener to bid a four-
card minor suit.  Assuming the partnership is playing a strong no-
trump, the 2S bid shows 9+ points and usually promises at least 4-5 or
5-4 in the minors.  Opener's responses to 2S are:

2NT:  A minimum hand with no four-card minor
3C :  A minimum hand with a four-card club suit
3D :  A minimum hand with a four-card diamonds suit
3H :  Showing or asking for a heart stopper, depending on agreement  
      Opener may have a four-card minor but is looking for 3NT
3S :  Showing or asking for a spade stopper, depending on agreement
      Opener may have a four-card minor but is looking for 3NT
3NT:  A maximum hand with no four-card minor
4C :  A maximum hand with a four-card club suit
4D :  A maximum hand with a four-card diamond suit

Responder's rebids are:

Pass :  Minimum hand
3C   :  At least a five-card suit; non-forcing
3D   :  At least a five-card suit; non-forcing over 2NT but forcing
        over 3C
3H/3S:  Respective splinters
3NT  :  Signoff
4C   :  Invitational if partner bid 3C; strong and forcing otherwise
4D   :  Invitational if partner bid 3D; strong and forcing otherwise

K96 Q3 QT87 AKJ                                 3 A2 AK532 Q9762

                           1NT  :  2S!
                           3D   :  3S!
                           4C   :  4D
                           4S   :  4NT
                           5D   :  6D
				  
  
Minor-suit Stayman is off in competition.


LEBENSOHL

Used when the opponents have overcalled 1NT.  A 2NT bid by responder
is a relay to 3C.  Most of the time responder usually has a weak,
one-suited hand.  The 1NT bidder must relay to 3C, which responder
can then pass with clubs or correct.  As a result, a direct new suit
bid by responder at the THREE level is forcing.

1NT (2C) 2NT!      2NT is a relay to 3C.

1NT (2C)  2H       2H is weak and natural.

1NT (2S)  3H       Responder has made a bid at the 3-level.  This is
                   natural and forcing.

Responders Rebids after the 3C Relay

Pass                                 : Weak hand with at least five
                                       clubs
New suit BELOW the overcaller's suit : Weak, natural

     For instance:

     1NT (2H) 2NT!
     3C!      3D           3D is a signoff bid showing at least five 
                           diamonds

New suit ABOVE the overcaller's suit : Invitational, natural

     For instance:

     1NT (2H) 2NT!
     3C!      3S           Since responder could have just bid 2S to
                           show a weak hand, he is now inviting game
                           in spades.

Cuebid of the enemy suit : Stayman, promising a stopper in the enemy
                           suit.  A direct cuebid would DENY a stopper.

     1NT (2H) 3H           3H is Stayman, denying a heart guard.

     1NT (2H) 2NT!
     3C       3H           3H is Stayman, promising a heart guard.  

3NT  : Natural, promises a stopper in the enemy suit.  A direct 3NT
       bid would DENY a stopper in the enemy suit.

     1NT (2S) 2NT!
     3C!      3NT         3NT shows a spade stopper.

     1NT (2S) 3NT         3NT denies a spade stopper.


CHAPTER 4- DOUBLES

RESPONSIVE DOUBLES

The responsive double a response to partner's takeout double after the
opponents have bid and raised a suit.  Sounds complicated?  Here it is
in bidding format:

1H - X - 2H - X!

The responsive double is based on the principle that a penalty double
here is usually unrewarding.  Therefore double shows scattered values
with at least 6 points and interest in locating a fit.  If the
opponents are bidding a minor suit, a responsive double asks partner
to pick a major suit.  If the opponents are bidding a major suit, a
responsive double requests partner to choose a minor suit.  For
instance, advancer might hold KT43 QJ32 93 JT9 and hear:

1D - X - 2D - ?

He should make a responsive double to ask partner to bid a major.
Note that a double by advancer is responsive only when the opponents
have opened a one-bid and raised it.  Some players also use the
responsive double when partner has made a simple overcall in a suit.
Modern Bridge Conventions by Bill Root and Richard Pavlicek gives an
excellent list of bidding situations in which double is NOT
responsive:

1C - X  - 1S - X

RHO has bid a new suit.

1C - 2S - 3C - X

Partner has made a jump overcall.

2H - X  - 3H - X

LHO has opened with a preempt.

1D -1NT - 2D - X

Partner has overcalled in no-trumps.

On the OKBridge 2/1 card, responsive doubles are on through 3S.


SUPPORT DOUBLES

Say you are first to speak holding AK4 KJT32 Q93 2.  You open 1H and
hear LHO pass.  Partner responds 1S (promising a five-card suit),
and RHO butts in with 2C.  Now what?  Users of the support double are
happy in this situation; they simply double to show a three-card
spade raise.  This lets them bid 2S to show a four-card raise.  When
was the last time you wanted to make a penalty double in this
auction, anyway?


When the opponents bid and raise a suit, support doubles are also on.

1C - 1H - 1S - 2H
X!

Finally, support doubles also apply when RHO makes a takeout double
rather than a simple overcall.  Redouble promises three-card support
while a simple raise shows four-card support.  So

1H - P - 1S - X
XX!

Promises 12-14 points with three spades.

On the OKbridge 2/1 card, support doubles and redoubles are on
through 2H.


CHAPTER 4- MISCELLANEOUS


CAPPELLETTI

Also known as Hamilton, Cappelletti is a defensive convention for use
after an opponent has opened 1NT.  The structure is:

X  : Penalty
2C : Any one-suited hand
2D : Both majors
2H : Hearts and a minor
2S : Spades and a minor
2NT: Both minors

Cappelletti may be used in both direct and balancing seat.

The 2C bid asks partner to bid 2D.  The overcaller passes 2D if his
suit is diamonds or corrects to the proper suit.  Responder may ignore
the 2D relay and pass 2C with a strong club suit, or he may bid two of
a major with a good 5-card suit.  He may also bid 2NT with 11-13
points and a balanced hand.

The 2D bid usually shows at least 5-4 in the majors (usually 5-5) and
requests partner to bid his better major.  With poor major-suit
support, partner is allowed to pass 2D with a good diamond suit or 3C
with a good club suit.  A 2NT response shows either a minor-suit hand
asking partner to bid 3C or 3D, or a limit raise in one of the majors.
In the latter case, advancer plans on rebidding 3H/3S after partner
has bid a minor.  As a result, an immediate response of 3H/3S to 2D is
preemptive, in accordance with the LAW.

The 2H and 2S bids are nonforcing.  Here too an immediate raise by
partner is preemptive.  When partner bids 2NT, he is either asking for
the minor or showing a limit raise.  For instance,

KQT52 43 AJT72 2                                    53 K98 K863 JT98
                       1NT - 2S!-  P  -  2NT!
                        P  - 3D -  P  -  P
                        P
Or

KQT52 43 AJT72 2                                    A987 K98 85 A432
                       1NT - 2S!-  P  -  2NT!
                        P  - 3D -  P  -  3S!
                        P  - 4S


ROMAN KEY CARD BLACKWOOD

The location of the king of trumps is a very important card when a
pair is looking for a slam.  Based on this principle, the Roman Key
Card convention modifies the responses to 4NT Blackwood by counting
the king of trumps as an ace.  Thus there are five "aces" for
responder to show, which he does in this scheme:

5C:  0 or 3 key cards
5D:  1 or 4 key cards
5H:  2 or 5 key cards without the queen of trumps
5S:  2 or 5 key cards with the queen of trumps

If a major suit is trumps and responder bids 5C, the cheapest step
bid by the RKC bidder asks for the queen of trumps.  Responder
denies the queen of trumps by bidding five of the major.  With the
queen he jumps to six of the major.  For instance:

                           1H     :     4NT(1)
                           5C(2)  :     5D (3)
                           6H(4)

1.  Roman Key Card Blackwood
2.  0 or 3 key cards
3.  Do you have the queen of hearts?
4.  Yes

If spades is trumps and responder bids 5D, the cheapest step bid by
the RKC bidder again asks for the queen of trumps:

                           1S     :     4NT(1)
                           5D(2)  :     5H (3)
                           5S(4)

1.  Roman Key Card Blackwood
2.  1 or 4 key cards
3.  Do you have the queen of spades?
4.  No

A partnership should decide what the 5NT rebid by the RKC bidder
shows.  Most experts use it to ask for the cheapest king.  With
the club king, for example, responder would bid 6C:

A987 KJT53 Q3 K3     				KQJT AQ982  AJ AQ4 
                              1H  :  4NT
                              5C  :  5NT
                              6C  :  7NT

Many experts also reverse the 5C and 5D responses to 4NT, because
they are more interested in looking for slam after partner shows
1/4 key cards instead of 0/3. This variant is known as 1430 RKC.

NEW MINOR FORCING

New Minor Forcing comes up when responder bids a new minor after
opener has rebid 1NT.  For example,

1C  : 1S
1N  : 2D!

2D is artificial, showing 11+ points and asking opener to further
describe his hand.  Responder is interested in game, normally has a
five-card major suit and wants to know if opener has support.  

Opener's responses, in order of priority, are:

Two of the other major     : shows a 4-card suit
Two of responder's major   : shows 3-card support, 12 to 13- points
Three of responder's major : shows 3-card support, 13+ to 14+ points
2NT                        : shows a stopper in the unbid suit, 12
                             to 13- points
3NT                        : shows a stopper in the unbid suit, 13+
                             to 14+ points
Raise of the new minor     : Natural, denies the ability to make
                             any other bid
Rebid of opener's suit     : Denies the ability to make any other bid

To show a genuine two-suiter, responder can rebid the new minor on
the third round.

New Minor Forcing is OFF in competition.



FOURTH SUIT FORCING (TO GAME)

When responder is an unpassed hand and rebids the fourth suit in an
uncontested auction, his bid is artificial, shows 12+ points, and is
game-forcing.  For example,

1D :  1S
2C :  2H!

2H is artificial and a game-force.  Opener's rebids, in order of
priority, are:

2 of responder's major      : 3-card support  
Any rebid of opener's suits : Natural, waiting
Raise of the fourth suit    : Tends to show 4-card support, waiting
2NT                         : Natural, with a stopper in the fourth suit

FSF does NOT apply in the following situations:

A)	1C : 1D
        1H : 1S

While 1S is forcing, it is not a game-force.

B) When responder's first bid is at the two-level, a fourth-suit rebid
is not artificial, since a game-forcing situation has already been
created.  For example:

        1S : 2C
        2D : 2H

C) When responder jump rebids the fourth suit.  For example:

        1H : 1S
        2C : 3D

    The jump rebid shows invitational values and at least 5-5 .  With
    a game-going two-suiter, responder could just do this:

        1H : 1S
        2C : 2D!
        2x : 3D


D)  In competition.

LEBENSOHL OVER PREEMPTS

2x - X - P - 2NT!

2NT is artificial, showing a weak hand and a desire to sign off at the
three-level.  The takeout doubler must relay to 3C, which partner can
pass (showing a weak hand with clubs) or bid 3D/3H/3S  (all signoffs).
As a result, if responder bids a new suit rather than go through 2NT
Lebensohl, he is making an immediate game invitation.

Example :

2H - X - P - ?

T3 T94 AJT32 976  Bid 2NT, and correct to 3D when partner bids 3C.

AQ T94 AJT32 986  Bid 3D, showing a good hand.

Advancer can make a mild game try by doing the following:

2H - X - P - 2NT!
P  -3C!- P - 3S

Since advancer could have bid 2S immediately to show a bad hand, and
3S to show a good hand, going through Lebensohl and then bidding 3S
shows a decent hand, about 6-9 points.  It does not promise extra
spade length.  Partner can bid game with a good hand of his own.

INVERTED MINORS

Originally an integral part of the Kaplan-Sheinwold system, Inverted
Minors exchanges the meanings of the simple and double raises of 1C/1D.  
For simplicity, the examples and situations described herein will be
based on an opening bid of 1C.
After 1C, a simple raise to 2C is a one-round force, promising at least
ten points and 4+ clubs.  A jump raise to 3C is preemptive, showing 5-8
points and at least five clubs (although excellent four-card support is
permissible).  Both raises DENY a four-card major.

AT2 J98 AK3 QT98                                   K93 T32 Q3 AJ654
                             1C  :  2C!

AT2 J98 AK3 QT98                                   T T32 Q932 KJ654
                             1C  :  3C!

Opener's rebids after partner has bid 2C are:

2D : 14+ points with a four-card diamond suit, forcing
2H : 14+ points with a four-card heart suit, forcing
2S : 14+ points with a four-card spade suit, forcing
2NT: Shows 12-14 with a balanced hand with adequate stoppers
3C : A catchall bid denying the ability to make any other bid.  
3NT: 18-19 points with a balanced hand

Responder's rebids to 2D/2H/2S are:
2NT                            :  10-12 with a balanced hand
3C                             :  A minimum unbalanced hand
3NT                            :  13-15 with a balanced hand
A raise of opener's second suit:  3+ trumps, invitational
A new suit                     :  Showing or asking for a stopper,
                                  depending on agreement
 
Some pairs play Inverted Minors in both uncontested and competitive
auctions.  On the OKbridge 2/1 card, Inverted Minors are off ONLY
over a takeout double.


Recommended titles   : Lawrence, Mike.  Workbook on the 2/1 System.   
                       Pavlicek, Richard and Root, Bill.  Modern Bridge            
                       Conventions.

Recommended websites : Shelagh Paulsson's 2/1 notes.
                       http://www.sns-access.com/~macaw/table.html

                       Anna Marsh and Wayne Flourney's description of
                       SA-YC and OKbridge conventions.
                       http://www.dircon.co.uk/am-graphics/sayc.htm
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