To help get opener back into the game, I've assigned the hand patterns to the sequences as follows:
|Pass||=||business redouble, or spades and a minor|
|Rdbl||=||clubs, or diamonds, or majors, or 3 suited short in a minor|
|2||=||clubs and a red suit|
|2||=||diamonds and hearts|
Now, after 1NT-(Dbl)-Pass-(bid), opener can double if he has spades and something in their suit. He can also double clubs if he has both minors.
Another advantage of this scheme compared to other similar ones is that responder's direct bids of two of a major are to play, and are thus much more preemptive than ones that had to go through two rounds of bidding.
Strong distributional hands can be shown by starting with 2NT (two suiters), passing and jumping to the three level (forcing one-suiters), or redoubling and jumping to the three level (invitational one-suiters).
Direct jumps to the three level are preemptive, but some
players might choose to psych