15 Balancing
The Defender who is to bid after 2 consecutive passes is in the Balancing seat.
His Partner is in the Direct seat. (The Direct seat has 0-15 pts. The Balancing seat is unlimited.)
Bidding
Balancing seat Direct seat
7-12 pts = Overcall, 5+card suit 0-11 pts = Pass
12-15 pts = Raise Partner's suit, 3+card support
12-15 pts = bid NT or new 5+card suit
9+ pts = Take-out Double
9-12 = with shape, 13+ = any shape
0-8 pts = Pass if RHO bids, otherwise
0-12 pts = bid 4+card suit, prefer unbid major
9-12 pts = bid NT
13-15 pts = jump bid 4+card suit, jump bid NT
11-15 pts = bid NT 0-10 pts = Pass, or bid longest suit when unbal.
11-15 pts = bid Crowhurst 2♣
Responses of Balancing seat after Crowhurst 2&clubs:
11-12 = bid suit at 2-level     13 pts = 2NT     14-15 pts = bid suit at 3-level