4C! 4H S/O 4D! 4S S/O
other the same as 4H opening other the same as 4S opening
4H 4S! H rkcb 4S 4N! S rkcb
4N! S CAB 5C! C CAB
5C! C CAB 5D! D CAB
5D! D CAB 5H! H CAB
5H S/O, 競叫 5S S/O, 競叫
5S 大滿貫迫叫 5N 大滿貫迫叫
CAB (4M+2~5M-1)
+1 無2控 no/3th control (+1=inv 6M)
+2 2控 2nd control (+1=ask K or singleton)
+3 1控 void
大滿貫迫叫 (5M+1)
+1 be solid if pn has 1 cds fit
+2 be solid if pn has 2 cds fit
+3 be solid if pn has trump Q or 3 cds fit
6M w/o trump A
7M solid suit