Siege

Opposite a passed hand, we open reasonable quality 4 card majors when 11-13 balanced, or when 11-13 unbalanced with a longer minor. We can also open a good 4 card diamond suit, intending to rebid 1S over 1H or to raise partner's major.

After a 3rd vul or 4th seat opening -
1M:2C is Drury
1M:2D is 5D4oM NF
1S:2H is 5H3S NF

After a 3rd NV opening -
1M:2C is natural, unbal, 11-12 points
1M:2D is Drury
1S:2H is 5H3S NF as above

In competition, 1M (overcall) - ?
1NT and 2C are natural
2D is a good raise
2H, after a 1S opening, is 5H3S NF

2D, 2H and 2S openings are all natural in 3rd+4th seats - 0-13 points, 5+cards in 3rd; 9-13, 6+cards in 4th.

After 1M:2C Drury -

• 2D = genuine opening bid, but not worth a GF. If partner now bids 2M, a new suit is a slam-try
• 2M (and 1S:2C, 2H) = sub-minimum opening, NF
• 2N = GF, natural
• New suit above 2M = natural slam-try
• Jump into a new suit = splinter

After 1M:2D Drury -

• 2M = suggestion to play
• 2H when spades agreed = genuine opening but not GF values
• 2N = natural GF
• New suit above 2M = natural game-try+