The Quantitative Raise

         If your partner's last bid was notrump, there are three ways you can end up in slam or grand slam:

 

         Invite 6NT.      A bid of 4NT is called a quantitative raise:

NT — 4NT:     Invites 6NT. (Partner should pass or bid 6NT.)

 

         Invite 7NT.      A bid of 5NT is a grand slam invitation:

NT — 5NT:     Invites 7NT. (Partner should either bid 6NT or 7NT.)

Note that partner must not pass the 5NT: you have decided to go to slam, and are inviting grand slam!

 

        Bid Slam.      A bid of 6NT or 7NT is final. Partner should not raise a bid of 6NT to 7NT.

 

        Example: After a 2NT Opening.      For example, after a 2NT opening (showing 20-21 HCP), you would make the following bids:

2NT — 4NT:     12 HCP (inviting 6NT).
  6NT: 13-15 HCP.
  5NT: 16 HCP (inviting 7NT).
  7NT: 17+ HCP.