Standard American
This is the commonest system played in america. It has many flavours, but has its roots in the system laid down bty Charles Goren.
The main features of the system are:
5-Card Majors
;
Strong NT
;
Two Clubs 19 To 21
;
Stayman
;
Jacoby Transfers
;
Weak Two Bids
;
For more information...
A Guide to Standard Bidding
by Richard Pavlicek
SA-YC Simplified