Jacoby 2NT PLUS - by responder or Opener

Inquiry 2 over 1 uses 2NT artificially as a MAJOR suit raise in a lot of situations. The basic situation is after partner opens 1H or 1S. Here 2NT shows a four card fit (or three cards with 16+ hcp, and no side five card suit) and limit raise or STRONGER hand. Only two example auctions, 1H-2NT, and 1S-2NT.

Jacoby 2NT is also used by opener, after 1m-1M-2NT. This shows a great hand with a four card fit. It is the STRONGEST fit showing response. Examples are 1C-1H-2NT, 1D-1H-2NT, 1C-1S-2NT, 1D-1S-2NT. We also play 1H-1NT-2NT as the same hand type (note 1NT promises five spades).

In competition, where one or the other partner has bid a major 2NT with a jump is also such a raise. A "slow 2NT" preceded by a pass, or a bid of a different suit, is not (obviously) Jacboy 2NT plus.

The responding scheme to this 2NT is pretty much the same regardless of how it is issued.

---> 2NT Jacoby 2NT Plus
--------> 3C, no game interest or monster slam interest
--------> 3D, Game interest, no slam interest, but better than 4M
---------------> 3H now ask partner to show shortness anyway.
--------> 3H, ask for 2NT bidder to show shortness if you have
-------> 3S short in "other major"
-------> 4C/4C short in bid suit (if not bid before naturally)
-------> 4M Just enough for game, no more