After a Third or Fourth
Seat opening of a Major suit, the responder, who is a passed hand, shows a
strong raise with at least 3-card support, and 10-12
point range, by bidding 2.
The opener will sign off on the Two Level with a minimum hand, and this is known as Reverse Drury. However, the opener will simply bid game with sufficient values, knowing of the 3-card support in the hand of his partner.
If the opener rebids 2 or the second Major suit, these rebids are
natural and forcing, and game is a strong possibility, especially if a second
fit is discovered.
As with all Partnership Agreements, it must be stated, that Opener can show a hand willing to accept an invitation to game by bidding any other suit.
Some expert bridge players use this new suit as a Help Suit Game Try.
Other bridge players play that the opening bidder must rebid 2
with any hand willing to accept an invitation to game. This allows the responder
to show a second suit or return to the trump suit with minimum invitational
values.
This is why the Partnership Agreement is so important.