TWO-WAY CHECKBACK
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?
 
Since “The Complete Book of Bridge” by Reese and Dormer (1984/5) followed by Philip Cowan in Bridge World 1988 and with improvements by Kit Woolsey in Bridge Today 1990 the discussion of how to sign-off, how to invite and how to impose game force have been tested by many partnerships. In Autumn 1994 was published in European Bridge pp 62-66 the XY no-trump by Lars Blakset & Soren Christiansen with mention of Crowhurst. The present scenario is for the use of 2-way checkback wrote by Kit Woolsey.

This convention 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 splinter 16+ hcp
   self splinter defines the major as trump suit
…………  Opener decides: 4
-sign-off/4NT-RKB
   4
<= 6133 splinter 16+ hcp
…………  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 define trump suit
   3
<= GF 1633 splinter 16+ hcp
…splinter Opener decides: 4
-sign-off/4-RKB
 3NT <= to play – balanced 12-17 hcp
   4
<= RKB1430 for Hearts GF 16+ hcp
   4
<= 3613 splinter 16+ hcp
…splinter 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 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 splinter 16+ hcp
splinter in 4
is in other minor – not support
the splinter defines the major as trump suit
…………  Opener decides: 4
-sign-off/4NT-RKB
   4
<= 6133 splinter 16+ hcp
…splinter 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
…………  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
…. 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
  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
<= 4-5 or 4-4 10-11 hcp inv
2NT <= invitation
11 hcp
  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 deny 4 cards 12-13 hcp
……….  Responder 3
ask for top honor
……….  So, without Opener must pass

 2NT <= denies 3
and 4 cards 2344
   3
<= denies 3 1minor 5 2335  
   3
<= 5-4 two minors 2245
   3
<= 4 and 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
    ?              
   2
<= 3 cards 12-13 hcp no top honor
   2
<= 3 cards 12-13 hcp 1 top honor
 ……. this is not a standard bid but is good
 2NT <= denies 3
4-4 minors 3
244
   3
<= denies 3 1minor 5  3235
   3
<= denies 3 2minors 452245
   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 sign-off
   2
<= 4 cards 12-13 hcp may have 3
   2
<= 3 cards – no 4 cards 12-13 hcp
……….  Responder 3
ask for top honor
……….  So, without 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
<= partnership agreement
   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 sign-off
   2
<= 3 cards 12-13 hcp no top honor
   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

Bottom Line: The Two Way Checkback should be played with a regular partnership. When you play with a new partner it is better to ask him what he plays: NMF CBS 2WCB. The use of the 4th suit is a fundamental tool to establish 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.