2-over-1 has quickly become the default system for US duplicate players, and for good reason. It's much better than old Standard American at quickly limiting hand ranges.
Which of course means that it's right at home in a strong club system after opening 1M. But because Opener is also limited, we get added benefits. In Eastern Mysticism, we never have to worry about:
- Opening 1M or 1NT with 15–17 HCP
- Jumping (and taking up valuable space) after a forcing NT
In addition, we can use Jacoby 2NT with invitational or better hands (instead of game-forcing). This means the direct 2M raise can be constructive, and forcing NT followed by 2M is to play—Opener will never jump past 2M.