1 of a major

1 no trump (discouraging for the moment)

   then 2 of a minor

   now 2 of the major = 5-7 h.c.p., 2 or 3 card support

1 of a major
 

8-9 h.c.p. and 3 card support = bid 2 of the major
immediately!

1 of a major
 

10-11 h.c.p. and 3/4 card support = bid 3 of the major
immediately!

1 of a major
 
 
 
 

4 of the major (immediately) = 5+ cards in your suit, we
   should make a game but not a slam.
* * This is a two-way action! * * In the unlikely event
that you cannot make the contract, you have pre-
empted the opponents out of what they can make.

1 of a major
 
 

2 no trump (ALERT! Jacoby) = I have an opening bid
also, 4 card support for your major… partner, tell me
more… bid shortness (singleton or void)

1 of a major
 
 

any bid at the two level is encouraging (10 or more
h.c.p.) and shows some cards/length in that suit, but
does not promise support for the major