Defending against 1NT (Lionel)
The system presented below was designed by Lionel Wright, and can be used against both a strong and a weak notrump. It does not use penalty doubles, which is hard to play even after a weak notrump. The weak notrump almost never gets a large penalty anyway. Instead, the method focusses on getting to a good contract for our side.
Versus a strong NT: Bid when you feel like it, the main purpose is
to get them out of this confortable contract. Two-suited bids may be
done on 4-4 hands.
Versus a weak NT: We want to find a good contract. Bid constructively.
Here are the responses to the opposing 1NT:
Double: + other suit or a very strong hand
The two-suited overcalls deny a good 5-card primary suit ( for double and for 2/), as 5M + 4m hands make the natural overcall.
Further bidding after double:
2: Pass or correct
2: Strong asking bid
2/: To play
Further bidding after 2/:
A suit bid is to play
2NT is a strong asking bid