Yellow Card Bidding System ● The partnerships want to play contracts in the following priority:
1) play a MAJOR suit contract first; or if not possible
2) play a NO TRUMP contract second; or as a last result
3) play a MINOR suit contract.
● After the suit or no trump is known, then determine the contract level to play.
Even though the opener bids No Trump (the second priority), the opener may not want to play No Trump. The opener cannot open a major suit without a 5-card major. But the opener may hold one or both 4-card major suits. This leaves the possibility of still playing a major suit contract (the number 1 priority).
As soon as the OPENER bids 2 NT , the partner (RESPONDER) knows what the final contract for the partnership will be. The responder knows the opener has 20 to 21 HCPs, no 5-card major and balanced, and knows the contents of its own hand. The opener does not have the big picture, so the opener must rely upon the responder to control the bidding and set the final contract. The responder will steer the bidding toward the final contract by using one of three paths.
The responses to a 2 NT opening are essentially the same as the responses to a 1 NT opening. The only differences are related to the point level thresholds used for bidding decisions. And since the opener has 20-21 HCPs, it is even more important to keep the much stronger opener's hand out of the dummy.
Path 1:5+card major and 0 to 12 HCPs - The partner will use the TRANSFER Convention to enter into a contract in that major suit. For details, visit the TRANSFERS (2NT) web page.
Path 2:4-card major (in one or both majors) and 5 to 12 HCPs - The partner will use the STAYMAN Convention to seek an 8-card fit in a major. For details, visit the the STAYMAN (2NT) web page.
Path 3:NO 4+card major and 5 to 12 HCPs - The partner will abandon the search for a major suit contract, and will explore a contract in No Trump, or in a minor suit. For details, visit the NO 4-card Major (2NT) web page.
When the partner holds 13+ HCPs, the partnership has enough points for a slam. The partner has two options on how to explore the possibilities of a slam:
• Bid 4 ♣ - Gerber. This artificial bid is asking for the number of opener's Aces.
• Bid 4 NT - Quantitative Invitation. This is a natural bid that is asking for the opener's points.
Visit the web page on Invitation to Slam.