Two-Way New Minor Forcing (a.k.a. xyNT)

Similarly to when we open 1NT, we need a system like stayman to discover any possible major suit fits after opener rebids 1NT (12-14). Responder can have one of a few potential problems. Here are a few things that need sorting out:

1) Responder has exactly game values and wants to figure out which game to play.
2) Responder has invitational values (11-12) and wants to invite game without getting too high in the process.
3) Responder thinks slam is possible and wants to investigate how well their hand fits with partner.
4) Responder just wants to play a part score contract.

The following convention sorts out most of responder's needs...

Two-Way New Minor Forcing. Also known as "xyNT" or Two-Way Checkback.

1m-1M-1NT

2 = relay to 2 to show ALL invitational hands
2 = Game ForcingCheckback
2 = Natural to play
2 = (after 1 response) Natural to play, (after 1 response) 4 4 invitational hand
2N = *Conventional
3 = Natural Slam Try
3 = Natural Slam Try
3 = Natural Slam Try
3 = Natural Slam Try
3N = Natural

after 1m-1M-1NT-2NT
2NT is a relay to 3,that's how you sign off in clubs, then over 3
Pass = Clubs
3 = 5 of my major, 4 of partners minor, low shortness
3 = 5 of my major, 4 of partners minor, high shortness
3 = 4 of my major, 5 of partners minor, low shortness
3!N = 4 of my major, 5 of partners minor, high shortness

SOME RULES:
1) Remember all invitational hands must start with 2, after the 2 relay every bid invites something, if you bid 2 then over partners 2 bid 3NT, that isinvitational to 4M, 5332 choice of games. Since we use 2NT for that gizmo, our NT invitation must start with 2 as well.
2) This system is on after 1-1-1NT and 1-1-1NT
3) This system is off in competition
4) When we jump rebid our major over 1NT it sets trumps and asks partner tocue bid for slam

This convention allows you to invite at the 2 level, rather than jumping. It allows you to set trumps directly over 1NT to initiate a cue-bidding auction. Responder is able to show their partner a double fit and show a particular singleton in order to avoid playing 3NT incorrectly and find a potential slam. There is very little downside to this convention and in my opinion even if you cut out the 2NT gizmo (the most difficult part to remember) then you are still far better off than playing regular new minor forcing. It is much easier and more effective than the standard convention 'New Minor Forcing"