A bidding system that originated in Taiwan in the 1960s and was the brainchild of C. C. Wei. It achieved world attention when the team from Nationalist China finished second in both the 1969 and 1970 World Championships.
The system is based on an artificial 1♣ (16+ points) opening, five-card majors and a 13-15 1NT. A 2♣ opening is natural while a 2♦ opening shows a three-suited- hand short in diamonds; 2♥ and 2♠ openings are weak twos. The range for the 1♥, 1♠, 2♣ and 2♦ openings is 11- 15, ie less than the 16 required to open 1♣.
When opener has a strong hand, the benefit of the system is that the partnership can establish a game force at a low level (any positive response creates a game force), making it easier to find the best game or slam. When opener has a weaker hand, the benefit is that responder knows opener’s strength better than in a natural system.
The disadvantages are that a 1♦ opening occurs commonly and says little about opener’s hand; in addition, vigorous opposing bidding can disrupt sequences that start 1♣.
