TWO-WAY CHECKBACK
Adapted frin Kit Woolsey with additional bids
Opener Responder
1minor 1major
 1NT       ?
How to search Opener’s hand also telling to Opener if the Responder’s bid is a sign-off or an invitation bid or a GF bid?

This convention of 2-way-checkback resolves the problems of NMF vs Walsh 2
sign-off and CBS vs 4 sign-off. The solutions are to search Opener’s hand inside two modalities. Game Forcing or sign-off/invitation. The asking bid in 2 is for sign-off or invitations and the asking bid in 2 is for GF sequences - like 2/1 GF:
Opener Responder
1minor 1major
 1NT     2
<= GF
   ? <= have you 3 cards support? 
---------------------
but the sequence
Opener Responder
1minor 1major
 1NT      2
<= not GF
is a forcing relay to Opener bid 2

to start a sign-off or an invitation 
and if hand fits may try game

---------------------------

Rule#1: After the sequence 1 minor response 1 major then 1NT the bid of 2 is GF and ask in first priority if Opener has 4 cards in the other major and in second priority if major has 3 cards support in the major bid.

Rule#2: After the sequence 1minor response 1major then 1NT the bid of 2 is a force relay to Opener bid 2 and if Responder next bid is 3 this is pure sign-off, and other bids are just invitation.

Rule#3: After the sequence 1minor response 1major then 1NT any bid in jump by Responder is GF (not more invitation) and obey the following meaning:

1-Summary of 1
response 1               
Responder Opener
……………   1
   
  
1  ……   1NT
    ?
   2
<= force relay to 2
   2 <= GF asks for shape
   2
<= choose 2 or pass
…………. 5
-4 or 5-5 5-9 hcp     
   2
<= sign-off 5+ cards 6-9 hcp
 2NT <= invitation 11 hcp  
…………. all next jumps are GF
   3
<= GF 5-5 or 4-5 12+ hcp
   3
<= GF 5-5 12+ hcp
   3
<= GF 5-5 12+ hcp
   3
<= GF 6+ cards 12+ hcp
………… this 3
jump define trump suit
 3NT <= to play – balanced 12-17 hcp
   4
<= RKB1430 for Spades GF 16+ hcp
         4NT is quantitative so 4
is always RKB
   4
<= 6313 self splinter 16+ hcp
   self splinter defines the major as trump suit
   letting partner decides if hands fit
   then Opener decides: 4
-sign-off/4NT-RKB
   4
<= 6133 self splinter 16+ hcp
   then Opener decides: 4
-sign-off/4NT-RKB
   4
<= to play - 6+ cards solid suit 12-15 hcp
 4NT <= quantitative invitation to 6NT 19 hcp
   5
<= to play – distributional 4-6 10+ hcp

2-Summary of 1
response 1       
Responder Opener
……………   1
   
  
1 ..…     1NT
    ?
   2
<= force relay to 2
   2 <= GF asks for shape
   2
<= sign-off 5+ cards 6-9 hcp         
   2
<= 4-4 11 hcp invitation
 2NT <= invitation 11 hcp
           all next jumps are GF   
   3
<= GF 5-5 or 4-5 12+ hcp
   3
<= GF 5-5 12+ hcp
   3
<= GF 6+ cards 12+ hcp
………… this 3
jump defines trump suit
   3
<= GF 1633 self splinter 16+ hcp
   then Opener decides: 4
-RKB/4-sign-off
 3NT <= to play – balanced 12-17 hcp
   4
<= RKB1430 for Hearts GF 16+ hcp
   4
<= 3613 self splinter 16+ hcp
   then Opener decides: 4
-sign-off/4NT-RKB
   4
<= to play 6+ cards solid suit
 4NT <= quantitative invitation to 6NT 19 hcp
   5
<= to play – distributional 4-6 10+ hcp

3-Summary of 1 response 1               
Responder Opener
……………   1
   
  
1  ……   1NT
    ?
   2
<= force relay to 2
   2 <= GF asks for shape
   2
<= choose 2 or pass
…………. 5
-4 or 5-5 5-9 hcp     
   2
<= sign-off 5+ cards 6-9 hcp
 2NT <= invitation to 3NT 11 hcp
              all next jumps are GF   
   3
<= GF 5-5 12+ hcp
   3
<= GF 5-5 or 4-5 12+ hcp
   3
<= GF 5-5 12+ hcp
   3
<= GF 6+ cards 12+ hcp
              this jump define trump suit            
 3NT <= to play – balanced 12-17 hcp
   4
<= RKB1430 for Spades GF 16+ hcp
   4
<= 6331 self splinter 16+ hcp
splinter in 4
is in other minor – not support
the splinter defines the major as trump suit
then Opener decides: 4
-sign-off/4NT-RKB
   4
<= 6133 self splinter 16+ hcp
then Opener decides: 4
-sign-off/4NT-RKB
   4
<= to play - 6+ cards solid suit 12-15 hcp
 4NT <= quantitative invitation to 6NT 19 hcp
   5
<= to play – distributional 4-6 10+ hcp

4-Summary of 1
response 1       
Responder Opener
……………   1
   
  
1  ……   1NT
    ?
   2
<= force relay to 2
   2 <= GF asks for shape
   2
<= sign-off 5+ cards 6-9 hcp         
   2
<= 4-4 11 hcp invitation
 2NT <= invitation 11 hcp   
   3
<= GF 5-5 12+ hcp
   3
<= GF 5-5 or 4-5 12+ hcp
   3
<= GF 6 cards 12+ hcp
              this jump define trump suit
   3
<= GF 1633 splinter 16+ hcp
then Opener decides: 4
sign-of/4NT-RKB
 3NT <= to play – balanced 12-17 hcp
   4
<= RKB1430 for Hearts GF 16+ hcp
   4
<= 3631 splinter 16+ hcp
the splinter 4
is in the other minor
the splinter defines the major as trump suit
…………  Opener decides: 4
-sign-off/4NT-RKB
   4
<= to play 6+ cards splinter 16+ hcp
 4NT <= quantitative invitation to 6NT 19 hcp
   5
<= to play – distributional 4-6 10+ hcp

5-Summary of responses for 2
 
sequence for sign-off or invitation
after
1 response 1  
Responder Opener

………….     1
      
  1
            1NT     
  2
*          2        
   ?    *
2 force relay to 2 
 pass <= probably 4
-6 up to 10 hcp
  2
<= 5-4 or 5-5 9-11 hcp
  2
<= 5 cards 10-11 hcp invitation
2NT <= shows Clubs 4
-5 / 5-5 9-11 hcp
…. Opener decides: pass / 3
sign-off / 3NT
  3
<= sign-off 4-5 6-9 hcp
  3
<= 5-5 9-11 hcp invitation
  3
<= 5-5 9-11 hcp invitation
  3
<= 6 cards 9-11 hcp invitation

6-Summary of responses for 2
 
sequence for sign-off or invitation
after
1 response 1  
Responder Opener

                   1
      
  1
            1NT      
  2
*           2        
   ?    *
2 force relay to 2 
 pass <= probably 4
-6 up to 10 hcp
  2
<= 5 cards 10-11 hcp invitation
  2
<= 4-5 or 4-4 10-11 hcp inv
2NT <= shows Clubs 4
-5 / 5-5 9-11 hcp
then Opener decides: pass / 3
sign-off / 3NT
  3
<= sign-off 4-5 6-9 hcp
  3
<= 5-5 9-11 hcp invitation
  3
<= 6 cards 9-11 hcp invitation

7-Summary of responses for 2

sequence for sign-off or invitation
after
1 response 1  
Responder Opener

                   1
      
  1
             1NT     
  2
*           2        
   ?    *
2 force relay to 2 
 pass <= probably 4
-4+ up to 10 hcp
  2
<= 5-4 or 5-5 10-11 hcp inv
  2
<= 5 cards 10-11 hcp invitation
2NT <= invitation
11 hcp
        all the follow jumps are invitation
        since Responder bids 2
first
  3
<= 5-5 9-11 hcp invitation
  3
<= 5-5 9-11 hcp invitation
  3
<= 5-5 9-11 hcp invitation
  3
<= 6 cards 9-11 hcp invitation

8-Summary of responses for 2
 
after
1 response 1  
Responder Opener

                   1
      
  1
           1NT      
  2
*           2        
   ?    *
2 force relay to 2 
 pass <= probably 4
-4+ up to 10 hcp
  2
<= 5 cards 10-11 hcp invitation
  2
<= 4-4 10-11 hcp invitation
2NT <= invitation
11 hcp good
  3
<= 5-5 9-11 hcp invitation  
  3
<= 5-5 9-11 hcp invitation
  3
<= 6 cards 9-11 hcp invitation

Summary for GF
Opener Responder
1minor 1major
 1NT      2
<= asks for in priorities:
   ?

- bid 4 of other major
- bid support of 3 cards
- rebid a 6-card suit garbage
- show distribution 2245 or 2254
- rebid 2NT

9-Summary GF 1
response 1
and Opener explain his hand
Opener Responder

   1        1
  1NT      2
<= GF checkback
    ?                
   2
<= 4 cards may have 3 cards
   2
<= 3 cards no 4 cards 12-13 hcp
….  Responder bidding 3
asks for top honor
….  Opener:
1087 K9 K1094 AK10 
….  Responder:
96432 AQJ QJ QJ6 
….  but without
Hxx Opener must pass
 2NT <= no 3
/4 cards 2minors 2344
   3
<= no 3 1minor 5 in 2335  
   3
<= no 3 2minors 5-4 in 2245
   3
<= 4-3 with 1+ top honor 14 hcp
   3
<= 3 cards with 1 top honor 14 hcp
 3NT <= 15 hcp singleton Spades 1
345

10-Summary GF 1 response 1
Opener Responder
  1        1
  1NT      2
<= GF checkback
    ?         not support for
or sign-off              
   2
<= 3 cards no top honor 12-13 hcp
   2
<= 3 cards 1 top honor 12-13 hcp
 ……. this is not a standard bid but is good
 2NT <= denies 3
4-4 minors 3
244
   3
<= no 3 1minor 5 in 3235
   3
<= no 3 2minors 45♣ in 2245
   3
<= 4 with 1+ top honor 14 hcp max
   3
<= partnership agreement
 3NT <= 15 hcp singleton Hearts 3
145

11-Summary GF 1 response 1
Opener Responder
   1       1
  1NT      2
<= GF checkback
    ?         not support for
or sign-off
   2
<= 4 cards 12-13 hcp may have 3
   2
<= 3 cards – no 4 cards 12-13 hcp
….  Responder bidding 3
asks for top honor
….  Opener:
1087 AK98 K1094 K10 
….  Responder:
J6432 J4 AQJ QJ6 
….  but without
Hxx Opener must pass
 2NT <= no 3
/4 and 4-4 minors 2344
   3
<= no 3 and 4-5 minors 2245
   3
<= no 3 1minor 5 cards in 2353
   3
<= 4-3 with 1+ top honor 14 hcp
   3
<= 3 cards with 1+ top honor 14 hcp
 3NT <= 15 hcp singleton Spades 1
345
 example Opener:
10 AQ9 AKQ9 98643

12-Summary GF 1
response 1
Opener Responder
   1       1
  1NT     2
<= GF checkback
    ?         not support for
and sign-off
   2
<= 3 cards no top honor 12-13 hcp
   2
<= 3 cards 12-13 hcp 1+ top honor
 …….. this is not a standard bid but is good
 2NT <= no 3
/4 and 4-4 minors 2344
   3
<= no 3 and 5-4 minors 2254
   3
<= no 3 1minor 5 cards in 3253
   3
<= 4-3 with 1+ top honor 14 hcp
   3
<= partnership agreement
 3NT <= 15 hcp singleton Hearts 3
145
 
example Opener: AQ9 10 AKQ9 108643

Note: In this Two Way Checkback we only use the sequence: 1minor – 1 major – 1NT, thus the sequence 1
response 1 – 1NT was not used here. Thus, we continue using the old Walsh Principle:
Opener Responder
  1
       1 <= may have 5-4major if 12+ hcp
……… if 4major-5
limited in 5-11 hcp bid first the major
  ?
 1major <=
5-4major   
 
Bottom Line: The Two Way Checkback should be played by a regular partnership. When you play with a new partner it is better to ask him what he plays: NMF or checkback because the 2WCB demands specific agreements. The use of the 4th suit is a fundamental tool to make a GF sequence asking for more explanation of partner’s hand, but the 4th suit is really GF only when it is bid at level 3.