1NT                 ?

                        - XX                  : transfer to 2§

                        - Pass              : force to bid redouble to opener if (4-4-3-2)

                        - 2§                  : Stayman

                        - Others            : system on

* Redouble used with weak hand with one minor or bicolor majors or bicolor minors

            X

            Pass     

1NT                  XX       

2§                   ?

            Pass

                        - Pass  : to play

                        - 2¨     : to play           

                        - 2©      : weak hand with bicolor majors

                        - 2ª      : weak hand with bicolor majors with long spades!

                        - 2NT    : bicolor minors

             X          

1NT                              Pass    (If responder bid Double after Pass, it’s penalty)

 ?                    

            Pass

- 2X      : to play with five cards

- XX      : S.O.S. with (4-4-3-2) distribution

- Pass  : (4-3-3-3)

            Pass

            Pass     

1NT                 Pass   

Pass                            ?

            X

                        - Pass  : to play

                        - 2§      : club and another suit (4-4)

                        - 2¨     : diamond and another suit (4-4)

                        - 2M     : to play with five cards

                        - XX      : transfer to 2§

                                               OVER CONVENTIONAL DOUBLE

           X one or two suit hand  

1NT                  ?

                        - XX                  : for busines

                        - 2§                 : Stayman

                        - Others            : system on