CHECK-BACK STAYMAN
Article by Woodgrove

Check-back is a convention used after 1x-1y-1NT (showing 12-14 or 15-17). 
Those of you that plays a natural system knows how difficult it is to make a forcing bid after this sequence. You often have to lye about a suit length. The check-back bidder must at least have an invitational hand, or if the 1NT-bidder has maximum you always end up in a game. Personally I like using 2 club as check-back, specially in pair tournaments, where 2 club seldom is the right contract. Those of you that wish to use the opposite minor suit I have written down those answers too. 


2 CLUB CHECK-BACK

1C-1H 
1NT-2C
2D :Min. not 3 Hearts. 
2H :Min. 3 Hearts. 
2S :Max. 4333. 
2NT :Max. 3334. 
3C :Max. 5 Club. 2 Heart. 
3D :Max. 3244 / 2245. 
3H :Max. 3 Hearts. 


1C-1S
1NT-2C 
2D :Min. Not 4 Hearts / 3 Spades.
2H :Min. 4 Hearts.
2S :Min. 3 Spades. Not 4 Hearts.
2NT :Max. 3334.
3C :Max. 5 club. 2 Hearts 
3D :Max. 2344 / 2245.
3H :Max. 4 Hearts. may include 3 spades. 
3Sp :Max. 3 Spar. Not 4 Hearts.


1D-1H 
1NT-2C 
2D :Min. Not 3 Hearts. 
2H :Min. 3 Hearts. 
2NT :Max. 3343. 
3C :Max. 2254 
3D :Max. 5 Diamonds. 2 Hearts. 
3H :Max. 3 Hearts. 


1D-1S
1NT-2C
2D :Min. Not 4 Hearts / 3 Spades.
2H :Min. 4 Hearts.
2S :Min. 3 Spades. Not 4 Hearts. 
2NT :Max. 3343.
3C :Max. 2254. 
3D :Max. 5 Diamonds. 2 Hearts.
3H :Max. 4 Hearts. May include 3 spades.
3S :Max. 3 Spades. Not 4 Hearts.


REVERSE MINOR CHECK-BACK
Those of you that want to play partners 1 minor opening suit on the two-level can use the other minorsuit as a check-back. The answers is like above, but after 1 club opening the answers is like this:

1C-1H 
1NT-2D (check-back) 
The answers are the same as after 2 club check-back but with these changes: 
2NT: Min. Not 3 Hearts. 
3NT: Max. 3334. 


1C-1S
1NT-2D
The answers are the same as after 2 club check-back but with these changes
2NT: Min. Not 4 Hearts / 3 Spades.
3NT: Max. 3343.


In Norway some players use 5 card spade opening and 1 club may be on 3 cards if 3433 / 4333.
Those of you that use this opening the answers are written in parantes. 

1H-1S
1NT-2C
2D : Min. 3433. 
2H : Min. 5 Hearts. Denies 3 Spades.
2S : Min. 5 Hearts. 3 Spades.
2NT : Max. 3433.
3H : Max. 5 Hearts. Denies 3 Spades.
3S : Max. 5 Hearts. 3 Spades.

FURTHER BIDS AFTER ANSWER ON CHECK-BACK
The only time you can stop below a game after check-back is if the opener has minimum
of what he has promised with his 1NT bid. This is what the answer hand bids in the second
bidding round:

- The first suit or partners opening suit on the 2-level is to play. 
- 2NT is natural and to play.
- Other bids are natural and game forcing, with exception from a jump after a natural bid.
This is a cue-bid.

If the opener shows maximum the gameforcing is made.

NECESSARY CHANGES AFTER CHECK-BACK
As previously mentioned you cant play 2 minor suit on the 2-level. 
These changes are therefore necessary, since 2 club / diamond is taken by
the check-back convention:

- 2NT is a not balanced limit hand in the suit that would have been check-back.
- 3 in minor in the suit that would have been check-back is to play.
With 11-12 Hcp and hand that is relatively balanced, it is better to bid check-back and
then 2NT if the opener has minimum. 2NT directly after 1NT, should show about 9-10 Hcp
and (preferably) a 6 card minorsuit. The opener then can judge his hand in the answers long
suit, in this way you can bid 3NT with relatively few points. Or maybe bid 5 in minor
with a very good fit. 

example:
after 2 Club check-back
1C-1S
1NT-2NT : Limit. 5+Clubs and 4 spades.
3C : To play (pre-emptive)

After reverse minor check-back
1C-1S
1NT-2NT : Limit. 5+Dimaond and 4 spades. 
3D : To play. (5)6+Dimaonds. 4 Spades.

OTHER CHECK-BACK POSITIONS:
Check-back is also a good to use after this sequence:
1C-1maj
2C
You now can use 2 diamonds as check-back. The strength is at least limit.

1C-1H 
2C-2D 
2H :Min. 3 Hearts. 
2NT :Min. 5 Clubs. Not 3 Hearts. 
3C :Min. 6+Clubs. Not 3 Hearts. 
3H :Max. 4 Hearts. (May include 3 spades)


1C-1S
2C-2D
2H :Min. 4 Hearts.
2S :Min. 3 Spades.
2NT :Min. 5 Clubs - 4 Diamonds.
2S/3D :Max. Not 3 Hearts.
3C :Min. 6+Clubs.
3H :Max. 3 Hearts.
3S :Max. 3 Spades.