"INVERTED MINORS" is part of a modern 2/1 system - 
Here we expose this convention with some particular adjustments and with a introdutory use of Roman Keycard Blackwood (RKB) for minors based on Kantar's book "Roman Keycards Blackwood" .

What is Inverted Minors conventions:
This conventions that apply after a minor (1C/1D) opening with no interference before Responder bids a directly support or indirectly for partner's minor opening bidding a splinter. The support 1C - 2C or 1D - 2D it is not a game force, so the bidding can stop at 2nt or at the agreed minor at level 3, but a splinter is a GF.

Playing SAYC a support in partner's  minor at level 2 shows 6-9 hcp and a support at level 3 shows 10-11 hcp. Using Inverted Minors convention these ranges are switched and the support at level 2 is 10+ hcp, so not limited at 11 hcp.
Opener Responder  ................... Opener Responder
  1C       2C <= 10+ hcp .............  1D        2D <= 10+ hcp
Opener Responder  ................... Opener Responder
  1C       3C <= 5-9 hcp ..............  1D        3D <= 5-9 hcp

Then Opener shows balanced hand minimum with 12-13 biddin 2nt or Opener rebid his suit at level 3 showing unbalenced hand with minimum. Thus Responder with 10-11 hcp may pass.

A polemic questions occurs about the number of cards to bid support for minor at level 2 (1C - 2C or 1D - 2D). Most partnership support at level 2 with 5+ cards when the suit is Clubs and admit support with 4 cards when the minor is Diamonds.

Our understanding after 1C opening, having 10+ hcp and both minors 5D-4C or 4D-4C, is make decision based in the best lead indication. If Diamonds have top cards and Clubs no, then we bid first Diamonds. In case Clubs have top honors and Diamonds no, then we bid first Clubs. Finally if both have equal top honors then we bid first Diamonds and after Clubs with 10-11 hcp, but with 12+ we bid always Clubs.

Of course the directly support for a minor, in principle, denies 4 cards major, but sometimes with a weak hand 5-7 hcp and also a poor major the preemptive minor support could be mandatory at level 3 to difficult interference.
Opener Responder
  1        3 <= 106xx xx KJ109xx Qx  (here preemptive bid is priority)
 Opener Responder
  1        1 <= 106xx x J109 AQxxx  (here to show the major is priority)

In other words, sometimes we need be flexible and not tied to the normal rules of the system, but partner should be aware that a 4 cards support to his minor opening it is possible.
Opener Responder                
  1C        2C <= Qx Qx Q10xxx AKJx (here indication of lead is priority)
 Opener Responder                
  1C        1 <= xx Jx AK10xx QJxx (here to show good Diamonds is priority)
ASKING FOR KEYCARDS FOR AGREED MINOR SUIT
 Rule#1: After a partnership agreed in a minor suit, using the inverted minors
convention, the jump by Opener to level 4 in the agreed suit ask for keycards using the RKB1430 (read aces-conventions) in 4 steps:
Opener     Responder
  1C             2C <= inverted minors 10+ hcp
  4C <= RKB1430 - special hand
 responses after 4C are:
- first      step => 4D  = 1 or 4 keycards
- second step => 4  = zero or 3 keycards
- third     step => 4  = 2 keycards without trump's Queen
- fourth  step => 4nt = 2 keycards with trump's Queen
Opener     Responder
  1D             2D <= inverted minors 10+ hcp
  4D  <= RKB1430 special hand
 responses after 4D are:
- first      step => 4  = 1 or 4 keycards
- second step => 4  = zero or 3 keycards
- third    step => 4nt = 2 keycards without Queen
- fourth  step => 5C  = 2 keycards with Queen

After an asking for keycard (RKB - Kantar's notation) if the asker bids the agreed suit this is a sign-off unless, by logic there are an exception, if the response of RKB shows 3 keycards, then the bid of agreed suit is not sign-off, but ask for the trump's Queen.

To avoid ambiguity the bid of the agreed suit at level 4 asks for keycard only after a jump or a splinter, else it is a sign-off by Responder showing 10-11 hcp or may be an invitation by Opener. So to avoid ambiguity the RKB asking for keycards should be done in the next suit at level 4 since if it is a suit not bid by a player.
Opener Responder
  1D        2D
  2 <= shows stopper in Spades and good 13 or 14+ hcp      
  .......... 3C <= shows stopper in Clubs but indefined strength
  3D <= denies stopper in Hearts - not forcing (13-14 hcp)
  .........  pass <= no stopper in Hearts and 10-11 hcp
  ------  3nt <= shows stopper in Hearts 12+ hcp
  ........   4  <= RKB1430 try to Slam
  ------   5D  <= to play

Opener Responder
  1D        2D
  2 <= shows stopper in and denies in Hearts
             3 <= shows stopper in and denies in Clubs
  4D <= denies stopper in C - not forcing
  .........   ?
             4D  <= sign-off - Opener must pass
             4  <= RKB1430 for Diamonds good hand 18+ hcp
             4  <= I can play in Spades Hxx or in 5D
             5D  <= good hand 13-17 hcp - to play

When the response of keycards does not denies or ensures the possession of trump's Queen (first and second steps of 1430 or 0314) the RKB asker may asks for the trump's Queen bidding the next suit and the responses for the Queen-ask are:
- return to the agreed suit denies trump's Queen;
- 4nt shows possession of trump's Queen and denies additional Kings;
- bidding a different suit confirm trump's Queen and shows the cheapest king up the line.

After RKB, if possible, 4nt is a Specific King Ask (SKA) else 5nt is a SKA:
Opener Responder
   1        2
   4 <= RKB1430 for - special hand
............   4 (1 keycard) or 4 (zero or 3 keycards)
    ?
  4nt <= Ask for Specific King
  5  <= Queen-ask after 4 and after 4 Queen-ask is 4
  5  <= sign-off for
  5  <= Specific Suit Ask (SSA) for Hearts
  5  <= SSA for Spades

Opener Responder
   1        2
   4 <= RKB1430 for
--------  4nt <= 2 keycards without trump's Queen        
............  5  <= 2 keycards with trump's Queen 
  5nt <= ASK

After RKB or a Queen-ask, a suit bidded, not the agreed suit, is a Specific Suit Ask (SSA) that wants to know the controls in this suit and the responses are:
 first step => Qxx or dubleton (third control)
 second step => Kxx or Kxxx (second control)
 third step => Kx or KQx (second and third  control)
 jump to the asked suit => singleton (second control without king)
 return to agreed suit => no control xxx (three losers)  

Example1 missing the trump's Queen
Opener Responder                     Opener                          Responder
   1C       2C <= 10+ hcp   x KQJx AKxx AKxx    KQx Axx Qx J10xxx
  4C   <= RKB1430
             4D <= 1 or 4 keycards (assume 1)
  4   <= partner do you have trump's Queen
  .......... 5C  <= no I don't have it
 pass <= missing 1 keycard and the trump's Queen

Example2
Opener Responder                     Opener                          Responder
   1D       2D <= 10+ hcp    AQJ x KJ109x AQ10x   Kx KQJ Axxx J9xx
  4D   <= RKB1430
             4 <= 1 or 4 keycards (assume 1)
  4   <= partner do you have trump's Queen
  .......... 5D  <= no I don't have it
 pass <= missing 2 keycard and trump's Queen

Note: Apparently the chances for Slam are not good since a significative incertainty exist in the Clubs suit due to the precipitate bidding made by the Opener in not bid a splinter in 3 that may correct the contract to 3nt.    

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Example3 missing additional Kings - information given by Queen-ask
Opener Responder                          Opener                        Responder
  1C       2C                         Ax Axx AQx K10xxx   QJx Qx xxx AQJ9xx
  4C       4D <= 1 or 4 keycards (assume 1)
  4  <= partner do you have trump's Queen
  .......... 4nt <= yes I have it but no Kings
  5C  <= no Kings, so let's stop the bidding now
  .......... pass

Example4 missing additional Kings - information given by Queen-ask
Opener Responder                         Opener                            Responder
   1D       2D <= 10+ hcp      Axx Axx Axxx AQ10   QJx QJx KQJ10xx J
  4D  <= RKB1430
             4 <= 1 or 4 keycards (assume 1)
  4  <= partner do you have trump's Queen
  .......... 4nt <= yes I have it but no Kings
  5D  <= no  Kings, so let's stop the bidding now
 ...........  pass

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Example5 response for specific King is 6nt when there are 3 Kings
Opener Responder               Opener                            Responder
   1       1                  Kx Kxx Kxx Axxxx    Axxx Ax Ax KQ109x
  1nt      2  <= nmf preparing to establish game force
  2nt      <= denies 4cards and 3 cards
  .......... 3  <= GF with Clybs agreed suit
  3nt <= stopper in all unbid suits
  .........  4  <= RKB1430 try for Slam
  4  <= 1 keycard
  .......... 4nt <= Asking for Specific King
  6nt <= 3 kings
 ...........  7  <= Kx in Spades because nmf deny support so 13 tricks

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Example6 after RKB we Ask for Specific King with 4nt
Opener Responder                 Opener                           Responder
  1       2                Ax AKJ10 AK109xx x   KJxxx xxx AJx xx
  2       3 <= playing Leb after reverse this is GF
  4  <= RKB1430 in Clubs
  .......... 4 <= show 1 keycard
  4nt  <= Asking for King do not promise all keycards it is a try for Slam
             5 <= shows King Spades denies K and K
  6   <= even missing one keycard it is a satisfactory try considering 6 cards .

Note: after the reverse bid Responder without any King, lets say with Qxxxx having 7 hcp should inform Opener about the strength of his hand bidding 2nt transfer to Clubs and then supporting Opener in Diamonds. Of course Opener with his strong hand will bid game in 5.

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Example7 after RKB and after SKA we search control in a suit with SSA
Opener Responder                              Opener                       Responder
   1       2D <= 10+ hcp       xx AKJ10x J109x Kx   Ax Qx AKQxxx Axx
  3D  <= 4 cards support ..........................       Specific Suit Ask (SSA) responses:   
             4D <= RKB1430 ...........................       first step => Qxx
  4  <= 1 keycard ....................................       second step => Kxx
             4nt <= Specific King Ask ............        third step => Kx or KQx
  5  <= Shows K ...................................        jump to agreed suit => singleton
 ...........  5 <= SSA do you have K ,,,,,,..        return to agreed suit => nothing  
  5nt <= second step so AKxxx
 ...........  7 I can count 13 tricks with Opener having 9 red cards
 pass

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Exemple8 another SSA after SKA
 Opener Responder                 Opener                            Responder
  1C       2C                        xx AKJ10x J109x Kx   Ax Qx AKQxxx Axx
  4C  <= RKB1430
  .......... 4 <= 2 keycards whitout Queen
  4nt <= Specifi King Ask
  .......... 5 <= shows K and denies KD
  5  <= SSA - partner what you have in Spades
  .......... 5nt <= third control (Qxx or Qx or xx)
  6C  <= let's stop in 6C
  ..........  pass

After a Specific King Ask a second King Ask have the follow responses:
- first      step => including 6nt shows Kxx(x)
- second step => Kx
- third    step => raise the ask-suit to show KQx
Without the King of the ask-suit Responder returns to the agreed suit

----------------------------------------------------
Example9 Search for another King after SKA
Opener Responder                          Opener                         Responder
   1D       2D <= 10+ hcp        AK AJxx AQxxx xx   xx KQx Kxxxx AKx
  4D  <= RKB1430
  .......... 4 <= 2 keycards whitout Queen
  4nt  <= Specific King Ask
  .......... 5 <= K and may have other King
  5  <= partner do you have the K?
 ........... 6 <= third step = KQ
 7nt  <= I can count 13 tricks
...........  pass

 SPECIAL CONVENTION FOR PASSED HAND
When a minor opening in third or fourth position receive a major response in jump at level 2 this means (fit showing) that the passed hand has 9-11 hcp concentrate in the two bidded suits with 5 cards in the major and 4+ cards in the minor opening. So the Opener bidding 2nt asks partner for the distribution of the passed hand and the answer in the minor opening shows 5422, otherwise the bid of an unbid suit suit shows singleton.
Note: When RKB asker knows that partner has 2 suits there are 6 keycards and 2 Queens to be answer in the RKB. If the RKB do not shows or denies the trump's Queen neither define it suit then the next suit ask for the Queen and the responses are:
step1 => 1 or 4 (1430) / 0 or 3 (0314) keycards and no Queen
step2 => 0 or 3 (1430) / 1 or 4 (0314) keycards and no Queen
step3 => 2 keycards and no Queen
step4 => 2 keycards and lower Queen
step5 => 2 keycards and higher Queen
step6 => 2 keycards and both Queens

Opener Responder
...........   pass
  1        2 <= Qx KQ10zx x A109xx 
 2nt        3 <= singleton (5521)

Opener Responder
...........   pass
  1        2 <= AQ10xx zx KJ10x Jx 
 2nt        3 <= no singleton (5422)

Example10 When hand fits 
Opener Responder                 Opener                            Responder
..........   pass               Kxx Ax AKx A10xxx    AQ10xx x 8x KJxxx 
  1        2 <= Spades and Clubs 9-11 hcp
 2nt  <= ask for distribution    
..........    3 <= singleton (5421)
  4 <= RKB1430 for Clubs
..........    5 <= fifth step -2 keycards and higher Queen (Q)
  7 <= considering 10 cards fit no need to have the Queen
             so we can count 13 tricks

===========================================
 INTERFERENCE AT LEVEL 3
After a minor suit is agreed if there are interference at level 3 the agreed suit bidded at level 4 is now just competitive for the partial score, not more a RKB.
Now to ask for RKB it is necessary a jump in the interference suit + 1:
if interference was in 3D then RKB is now bidded at 4;
if interference was in 3 then RKB is now bidded at 4;
if interference was in 3 then RKB is now bidded at 4nt.
 
============= INVERTED MINORS ====================

Once inverted minors is established this convention needs a strategic bidding plan to know if:
a) auction should be stop at level 3 in their agreed minor suit;
b) auction should be stop at level 2 in 2nt due to limited hands;
 c) search if they can rather bid 3nt than 5C/5D;
d) search if they can try a Small Slam or even a Grand Slam.

 Rule#2: The Opener shows a weakness hand (12-13 hcp):
1.1- bidding 2nt with a balanced hand (4333 or 4432), generally
        with 3 card in the opening suit with stoppers in both majors
        stoppers are: A.., Kx.., QJx, Q10x, J10xx, J9xx;
        Opener Responder                  Opener Responder
         1C        2C .............................  1D        2D
         2nt <= Responder can pass    2nt <= Responder can pass
1.2- rebidding his opening suit shows unbalanced distribution like 5431 or
        6331 or 5332, or even 5422 without stopper in a major.
        Opener Responder                  Opener Responder
         1C        2C .............................  1D        2D
         3C  <= Responder can pass    3D <= Responder can pass
corollary: after Opener shows weakness Responder can pass having less
than 12 hcp or even with bad 12 hcp and no sure stoppers found in a suit.

 Rule#3: When the Opener have 13-14 hcp with good intermediates cards (9/10/J) making good stoppers like K109, QT98, Opener must bid his first sure stopper (Qx is not a sure stopper) in a crescent ranking. A non bid suit means no stopper in that suit, but the bid of a suit at level 3, already denied full stopper at level 2, means a semi-stopper (Qx or Jxx).

Note: If Opener has balanced 15-17 and stoppers in 3 suits his opening should be  1nt and not in a minor suit.

 Rule#4: When the Opener have 18-19 hcp with balanced hand (4333 / 4432 / 5332) Opener second bid should be 3nt promising stoppers in all unbid suits. Then  Responder became the captain for the final contract and he can:
 a) pass;
 b) ask for keycards bidding his minor suit at level 4;
 c) cue bidding in a singleton or void or ace at level 4;
 d) sign-off the auction with a jump to level 5 at the agreed minor suit.

 Rule#5: with 13+ thru 15 hcp and a singleton/void Opener can do a splinter at level 3 to establish a GF auction. Then Responder became the captain for the final contract and may bid 3nt with good values in his partner singleton/void.
5.1- Opener          Responder
          1C                   2C
     (3D/3/3) <= splinter
5.2- Opener          Responder
          1D                  2D
     (3/3/4C) <= splinter
Note: after the splinter, that limits the strength of Opener's hand, Responder bidding the agreed minor suit shows a minimal hand with 10-11 hcp and no interested in game, so Opener may pass in the agreed suit at level 4 or bid game in the agreed suit with his maximum hand.
In case Responder bids the next suit after the agreed minor suit this is a RKB1430.
Example11
Opener Responder
  1C        2C
  3 <= splinter (12+ hcp)
              ?
    3  => cuebid (first or second control) and GF (12+ hcp)
    3nt => to play (12-15 hcp)
    4C  => sign-off (10-11 hcp)
    4D  => RKB1430 for Clubs
    5C  => to play (12-15 hcp)

 Opener Responder
  1D        2D
  3 <= splinter (12-14 hcp)
              ?
    3  => cuebid (first or second control) and GF (12+ hcp)
    3nt => to play (12-15 hcp)
    4D  => sign-off (10-11 hcp)
    4  => RKB1430 for Diamonds  
    5D  =< to play (12-15 hcp)
Note: These cuebids could be singleton/void or A / KQ / KJ

Rule#6: After the opening in a minor suit, if opponent pass, Responder with 12-15 hcp and singleton in a major having 5+ cards support in partner's minor, should splinter at level 3. These splinters GF are important to show if the singleton works or not (fits) for game and even for a possible Slam. So in continuation Opener may use cuebid or RKB by showing that splinter fits. Opener bids the agreed suit when splinter does not fits.
 6.1- Opener        Responder
            1C           3D/3/3   <= splinter 13-15 hcp GF with 5C+ cards
            ?
           3nt <= to play
           4C  <= not forcing - minimum
           4D  <= RKB1430
6.2- Opener        Responder
            1D           3/3/4C   <= splinter 13-15 hcp GF with 5D+ cards
            ?
           3nt <= to play
           4D  <= not forcing - minimum
           4  <= RKB1430
Exemple12 Responder makes mini splinter GF
Opener Responder      Opener: A8x KJx DKJx Cxxxx
    1C        3          Responder: Qxx x DA9xx CKQJxx
    4C  <= signoff
    .......... pass (minimal hand

Exemple13
 Opener Responder      Opener: AKxx Jxx Dx CAxxxx
    1C        3          Responder: Qxx x DAKxx CKQxxx
    3  <= cuebid - hand fits
                4D  <= RKB1430 (4 shows minimal hand 12-13 hcp)
    4nt <= third step - shows 2 keycards without Queen
                6C Opener may have AK Spades and nothing h or ace h with control
   pass
   
Exemple14
 Opener Responder      Opener: AKxx Axx Dx CAJxxx
    1C        3          Responder: Qxx x DA9xx CKQxxx
    4D  <= RKB for Clubs (4C without jump is sign-off)
    .........  5C <= fourth step 2 keycards with Queen
    5  <= SSA partner what you have in Spades?
               5nt <= first step means third control (Qx or Qxx or xx)
    7C       pass
Rule#7: After the opening in a minor, if opponent overcall at level 1, there are
no more inverted minors conventions, and splinter in jump is off by Responder,
so if Responder bids a:
a) jump to level 2 he shows a weak hand with 6 cards;
b) jump to level 3 he shows a weak hand with 7 cards,
    in both cases < 6 hcp and with A or K at top and good middle cards;
c) cuebid as invitation hand with 5+ cards support and 10-11 hcp;
d) simple raise in Opener's minor means 4+ cards support with 6-9 hcp.
7.1- Opener   Overcaller  Responder   Weak Jump Shift
             1C         1D              2 <= xx KJ109xxx Dxx Cxxx
            1C         1D              3 <= x A10987xx  Dxx CJxx
            1C         1D              2 <= AJ10xxx xx Dxx Cxxx
            1C         1D              3 <= KQ10xxxx x Dxx Cxxx
            1C         1              2 <= AJ10xxx xx Dxx Cxxx
            1C         1              3D <= xx x DAJ10xxxx Cxxx
            1C         1              3 <= KQ10xxxx x Dxx Cxxx
            1C         1              3D <= xx x DKQ10xxxx Cxxx
             1C         1              3 <= x A10987xx Dxx CJxx
7.2- Opener   Overcaller  Responder  Weak Jump Shift
            1D         1              2 <= AJ10xxx xx Dxx Cxxx
            1D         1              3C <= xx x Dxxx CKQ109xxx
            1D         1              3D <= xx x DAJ10xxxx Cxxx
            1D         1              3 <= KQ10xxxx x Dxx Cxxx
            1D         1              3C <= xx xx Dxx CAJ987xx
            1D         1              3 <= xx KJ109xxx Dxx Cxxx
7.3- Opener   Overcaller   Responder    support with 6-9 hcp
            1C      1D/1/1     2C <= xxx Kx D10xxx CKQ9x  
            1D      1/1/2C     2D <= Qx Jx DA10xx CQ9xxx
7.4- Opener   Overcaller   Responder    support with 10-11 hcp
            1C         1D              2D <= Axx Q10x Dxx CKQ9xx 
            1C         1              2 <= Axx x DJ9x CKQ9xxx 
            1C         1              2 <= xx Q10x DQJx CAQ9xx 
            1D         1              2 <= Kxx x DA10xxx CQ9xx
            1D         1              2 <= xx Kxx DKJ10xxx CK9
            1D         2C              3C <= Kxx Ax DQJ10xxx Cxx
     
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 OPENER'S SECOND BID AFTER 1C OPENING RESPONSE 2C INVERTED MINORS:
Opener Responder
    1C         2C
     ?
second bid by Opener:
    2D  => 14+ hcp and stopper in D(interested in 3nt) show your stopper
    2  => 14+ hcp and stopper in and no stopper in D, is 3nt possible?
    2  => 14+ hcp and stopper only in , is 3nt possible?
    2ST => minimum with stopper in both majors, maybe only 3C cards
    3C  => minimum unbalanced hand maybe 5431 with singleton in a major
    3D  => 14-16 hcp - splinter GF - if Responder bids 4C is sign-off 10-11 hcp
    3  => 14-16 hcp - splinter GF - if Responder bids 4C is sign-off 10-11 hcp
    3  => 14-16 hcp - splinter GF - if Responder bids 4C is sign-off 10-11 hcp
Note: after splinter Responder, the weak hand, bidding 4D is RKB0314 and 4C ahows 10-11 hcp and no fits, but 5C shows 10-11 when hands fits.  
    3ST => strong balanced hand with 18-19 hcp, Responder bids game/Slam
    4C  => RKB1430 asking for keycards
    4D  => 6C-5D distributional weak GF Responder decide: 5C or 6C
    4  => 6C-5 distributional weak GF Responder can pass with 3 cards 
    4  => 6C-5 distributional weak GF Responder can pass with 3 cards
    5C  => to play - weak hand and long Clubs suit maximum 2 key cards
    5D/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

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RESPONDER'S SECOND BID AFTER OPENER SECOND BID IN 2nt 
Opener Responder
  1C       2C
 2nt       ?
           pass => with 10-11 hcp and only 4C cards
             3C  => sign-off having 5C 10-11 hcp, possibly singleton in major
             3D  => shows 12+ hcp with stopper (A/K/QJx) in D
                           Opener sign-off the auction in 3nt or in 4C
             3  => shows 12+ hcp with stopper in , no stopper in D
                           Opener sign-off the auction in 3nt or 4C
             3  => shows 12+ hcp with stopper in , no stopper in D and
                           Opener sign-off the auction in 3nt or 4C
            3nt  => shows 13-18 hcp with stopper in D 
             4C   => RKB1430 asking for keycards - try to Slam
             4D   => splinter 16+ hcp try for Slam - 4nt by Opener is RKB0314
             4   => splinter 16+ hcp try for Slam - 4nt by Opener is RKB0314
             4   => splinter 16+ hcp try for Slam - 4nt by Opener is RKB0314
Note: the splinter is important because it can under valorize or upgrade Opener's hand, so Opener, the weak hand, decides for RKB0314 bidding 4nt to try 6C or if not fits to sign-ff bidding 5C.
             5C   => to play - sign-off
5D/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

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RESPONDER'S SECOND BID AFTER OPENER 3C 
Opener Responder
  1C       2C
  3C        ?
           pass=> with 10-11 hcp and no good distributional hand for bid 5C
             3D => shows 14+ hcp and stopper in D, now Opener must bid his
                           major stopper or 4C that is not Gerber in this sequence after  
                          have show weakness, but just sign-off
             3 => shows 14+ hcp  and stopper in , but deny stopper in D, so
                          Opener bid his stopper in only if he has also a stopper in D-
                          Opener 4C, shows no condition to play 3nt, but Opener with
                          both stoppers in Dand in must bid 3 giving condition for
                          Responder bid 3nt with a balanced 4333 hand having good
                          stoppers in and semi stoppers in the others.
             3 => shows 14+ hcp and stopper in , now Opener must bid 3nt if
                         he has stoppers in reds ( D), so in a 5431 with singleton
                         in D he can jump to 5C, or with 2 losers in D he sign-off in 4C.
             3nt=> to play - 14-18 hcp - shows stoppers on unbidden suits
             4C => RKB1430 asking for keycards - try for Slam
        4D/4/4 => splinter singleton 16+ hcp with 5C+ and interesting in Slam
 Note: the splinter is important because it can under valorize or upgrade Opener's hand. Thus Opener, the weak hand, decides for RKB0314 bidding 4nt to try 6C or if hand not fits to sign-ff bidding 5C.
             5C => to play - sign-off
         5D/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

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OPENER'S SECOND BID AFTER RESPONDER'S WEAK RAISE TO 3C
Opener Responder
  1C       3C
   ?
 pass => nothing to try
  3D => asking if Responder have a major singleton? if not 4C sign-off
                 Responder bids 3=singleton / 3=singleton  / 4C sign-off        
  3 => very good suit with 4 cards,  can we play in a 4-3 fit?
                if not decide for 4C sign-off or  5C game 
  3 => very good suit with 4 cards, can we play in a 4-3 fit?
                 if not decide for 4C sign-off or 5C game
  3nt => to play - strong hand - possible 3C with 18-19 hcp
  4C => RKB1430 asking for keycards (he the sign-off is pass in 3C)
  4D => 6C-5D distributional - Responder must bids a major ace or 5C
  4 => 6C-5 distributional hand GF Responder can pass with 3 cards 
  4 => 6C-5 distributional hand GF Responder can pass with 3 cards
  5C => to play - sign-off

**********************************************************
 OPENER'S SECOND BID AFTER 1D OPEN AND 2D INVERTED MINORS 

Opener Responder
    1D         2D
     ?
    2  => 14+ hcp stopper in (interested in 3nt), show you stopper
    2  => 14+ hcp stopper in , deny stopper in , is 3nt possible?
    2nt => weak 12-13 hcp - stopper in both majors - maybe only 3D cards
    3C  => 14+ hcp stopper in C, deny stopper in majors, is 3nt possible?
    3D  => minimum (12-13 hcp) unbalanced hand, Responder is now captain
    3  => splinter 14+ hcp and singleton , cue bid / Gerber / 4D sign-off
    3  => splinter 14+ hcp and singleton , cue bid / Gerber / 4D sign-off
    3nt => strong balanced hand 18-19 hcp Responder decide: game or Slam
    4C  => splinter
    4D  => RKB1430 asking for keycards
    4  => 6D-5 distributional weak, Responder can pass with 3 cards
    4  => 6D-5 distributional weak, Responder can pass with 3 cards
    5D  => to play - weak hand and long Diamonds suit - only 2 key cards
 5C/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

*************************************************
RESPONDER'S SECOND BID AFTER 2NT:
Opener Responder
    1D      2D
   2nt      ?
            pass=> pass 10-11 hcp and only 4 cards D
             3C  => stopper in C (A/K/QJx) 12-14 hcp - singleton in a major?
             3D  => sign-off with 5D and 10-11 hcp - singleton in a major
             3  => stopper in (A/K/QJx) and deny stop in C- game try
             3  => stopper in , deny stopper in C and - game try
            3nt => to play - promise stopper in C 
             4C => splinter
             4D => RKB1430 asking for keycards
       4/4/4C => splinter - 16+ hcp with 5D+ and interesting in Slam
Note: the splinter is important because it can under valorize or upgrade Opener's hand, so Opener can decides if it is possible to try a Slam or just sign-off in 5D
              5D => to play - sign-off
5C/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

**********************************************
RESPONDER'S SECOND BID AFTER OPENER 3D 
Opener Responder
  1D       2D
  3D       ?
          pass => with 10-11 hcp no good distribution for bid 5D
           3  => 14+ hcp  - stopper in ,  bid your stopper or 4D sign-off
                        Opener with stopper in bid 3nt, with singleton bid 5D 
                         and with 2 losers in bid sign-off in 4D
           3  => shows 14+ hcp and stopper in , but deny stopper in , now
                       Opener can bid 3nt only having stopper in and C, otherwise
                       jump to 5D with singleton in and with 2 losers in Opener
                       must sign-off in 4D
          3nt  => to play - 14-18 hcp - stop in all unbid suits
           4D  => RKB1430 asking for keycards
     4/4  => splinter - 16+ hcp with 5D+ Slam interesting
Note: the splinter is important because it can under valorize or upgrade Opener's hand, so Opener can decides if it is possible to try a Slam or just sign-off in 5D
           5D => to play
5C/5/5 => exclusion RKB1430 - Responder has void in the suit being bid and is trying Grand Slam asking for ignore the ace of his void in the answer.

**************************************************
OPENER'S SECOND BID AFTER RESPONDER RAISE WEAK TO 3D
Opener Responder
  1D         3D
   ?
 pass => nothing to try      
  3 => very good suit with 4 cards,  can you play in a 4-3 fit?
               if not decide for 4D sign-off or  5D game 
  3 => very good suit with 4 cards, can you play in a 4-3 fit?
               if not decide for 4D sign-off or 5D game
 3nt => to play - strong hand - possible 3D cards with 18-19 hcp
   4D => RKB1430 asking for keycards (to sign-off just pass)
  4 => 6D-5 distributional hand - Responder pass with 3 cards or 5D
  4 => 6D-5 distributional hand - Responder pass with 3 cards or 5D
  5D => to play - sign-off     


***********************************************************
 VERIFY YOUR BID IN THE FOLLOW HANDS:

In all questions your partner open 1C and no interference
1)  J754  5 D KJ4 C AK873            what is your bid?
Answer: bid 1, you should not raise to 2C denying a major because you have a good response hand and so there are no worry against opponents bidding in the auction. By the way, sometimes it is good to know possible distribution of cards with interference and where are the missing hcp, but suppose your hand is:  
 J754  54 D J4 C A10872, now a weak bid in 3C it is not wrong, because this brings difficulty in opponents interference to organize a competitive auction.
Another variable to consider in the bidding is the indication of lead, If your hand is A754  54 D J4 C J10872 then now the normal bid of 1 is the right option.

2)  KJ9    K105 D Q107 C Q987    what is your bid after 1C opening?
Answer: here we can select two possibilities: 1) 2C or 2) 2ST.
2nt may be better because your hand has stoppers in all unbid suits and it is a balanced hand. If you have a similar hand with 13 hcp then 2C is the correct bid.
By the way with 13 hcp you can't bid 3nt, because the response of 3nt for any opening in suit at level 1 means another 1nt opening hand with 15-17 hcp without a 5 cards suit.


3)  8  A106 D KQ9 C J98732           what is your bid after partner 1C? 
Answer: here we have two options: 1) 3 or 2) 2C.
So the partnership must have an agreement about the use of mini splinter after minor opening.
Max Hardy in his book "Standard Bridge Bidding for the for 21st Century" emphasizes Splinter bids as the best modern bidding tool bridge because expresses a fit and indicates a singleton (or void) thus permits Opener a revaluation the power of his cards.
Thus the correct bid is 3 having 12 points (10 hcp + 2 for additional cards). Some partnership may decide to bid 2C because splinter is GF and there are only 11 hcp in this hand, but this hand justify a splinter.

In case of interference there are no more splinter and no more inverted minors structered sequences, thus we cuebid to show invitation (10-12 hcp) having support with 5C+ cards So, if partner opening is 1C and opponents overcall 1, we cuebid 2 as invitation hand and splinter 3 if we have the same values with a singleton in opponent suit.
In case we have a long and weak suit we use the Weak Jump Shift (WJS) convention  to show a weak 7 cards invitation to game, example:
Opener Overcaller Responder
   1C         1           ?
                               2 => invitation    8 A86 DKQ9 CJ98732
                               3 => invitation    A98 6 DKQ9 CJ98732
                               2 => weak 6        K109543 62 D92 CJ92
                                    => weak 6        KJ8763 6 D972 CJ92
                               3 => weak 7        KQ109654 xx Dxx Cxx
                                          weak 7        AJ109854 x Dxx C10xx
Opener Opponent Responder
   1C        pass        3   =>  8A86DKQ9CJ108732 splinter


4)  J7  Q54 D J4 C KQ8732           what is your bid after partner 1C?
Answer: Here we may have a indecision between response 2C or 3C.
We have only 9 hcp but support of 6 cards has a value of 2 points that is not compute for inverted minors, besides we have only 1 king, and 2 bad jacks.
Thus, it is more important jump as weak hand 3C to put difficulty in opponent interference showing a lead for his partner.


5)  KJ9    765  D Q107 C KQ87      what is your bid after partner 1C?
Answer: here the indecision is between 2C or 2nt.
Without stopper in it is better a bid 2C and have a more scientific search for hearts stopper. Of course if Opener bids 2nt or 3C we should pass.


6)  K108   AQ9 D QJ10 C KJ95     what is your bid after partner 1C?
Answer: here we can bid 2C or 3nt (16-17 hcp).
The 2C is correct response because you should not deny good 4 cards support, but as exception, this hand is perfect to 3nt to receive a present of one trick in the lead, and because it is a 4333 distribution that has no need to ruff in the dummy.
Preference for 3nt is also because in one bid Opener will know your shape and range, even though we are showing a 4333 hand with 4D cards and 3C cards.
However if Opener have a 16-17 hand with 5431 or 4441 singleton Diamond we may lose a possible 6C. It is a hard decision.


7)  A4  54 D AKJ104 C K875        what is your bid after partner 1C?
Answer:  Here are two possibilities: bid 2C or 1D.
If we don't have A, so only 11 hcp then 1D is good option include as indication to lead and after Opener bids 1nt we can bid 3C to show support with 10-11 hcp.  
But with 15 hcp if partner really have Clubs suits with 4C+ we can also think in Slam if partner have 2 aces.
A good convention in the Inverted Minors may permit a more clear shape and range of Opener hand to make a more scientific auction.
If we bid 1D Walsh and partner bids 1nt, what should be the best continuation for Responder with doubleton in the majors?
So the only bid we have here is 2C and we will know the best contract with the help of our good Inverted Minors Convention.


8) J 5 DQ1074 CQ987542      what is your bid partner 1C?
Considerations: It is interesting that an overcall did not occurs. Partner can have 18-19 hcp or a normal open with both majors and 3 cards in Clubs. Independent of the
vulnerability 3C is the better bid to tell partner that we have only clubs.
So, if opponent double and find a major fit, partner before double the auction must consider they can ruff clubs and possible CAKx will not make trick.
Finally, if we are nVul and they are Vul, we also can think in bid directly 5C to sign-off the bidding even partner has 18-19 hcp he need pass after 5C.


9) A98 Q86 D9 CK109832      what is your bid after partner 1C?
Answer: We already saw a similar hand and we must consider this hand as invitation hand - not weak - the bid is 3D splinter, in case of interference we cuebid the overcaller's suit to show invitation. In case partner bids 3nt we may correct the contract bidding 5C, but sometimes 3nt make and 5C down 1.


10)  AJ9  AKJ D 7 C KJ10987      what is your bid after partner 1C?
Answer: we have a strong 17 hcp but we must know about the shape of Opener hand. The king Spades is a vital card to put us in a Slam or Grand Slam. Opener
can open with only 3 cards and the CQ could be third.
So, the normal bid is 2C and after Opener shows more precisely his hand we should have take charge of the bidding.


11)  KQ9  - D KQJ10 C AKJ985   what is your bid after partner 1C?
Answer: this is really a strong response hand.
We need know A, AD and QC, so EKB Exclusion RKB gives us these information. We also should search for trump's Queen and after EKB we bid the next suit this for  Queen-ask.  Knowing the mechanism propose for Kantar we will have all conditions to bid only 6C or bid 7C. Read www.bridge.pro.br1aces-conventions.htm the topic about Exclusion RKB the information about EKB for minors.
Thus the better strategic is first bid 2C to define the agreed suit and after known the shape of Opener's hand we may go to EKB bidding 4 if possible or 5 to know how many aces, excluding ace Heart, partner has.
Opener                  Responder
  1C                         2C
   ?
  2D                         3 splinter and 4 <= EKB
  2                         4 splinter and 5 <= EKB
  2                         4 splinter and 5 <= EKB
 2nt                         4 splinter and 5 <= EKB
  3C                         4 splinter and 5 <= EKB (4 is splinter)
  
   
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