[ilink url=»http://www.abfevents.com.au/events/ayc/2014/bulletins.asp»]Source: 
Bulletins por Modi[/ilink]
Checkback, and it’s variations, is an incredibly useful convention. Nearly all top players play some variation of Checkback, which range in complexity and descriptiveness. We will cover a range of versions of Checkback later in the article.
Relevant side article (Rebid Style):
Assuming you are playing strong 1NT (15-17), and you open 1
and partner bids 1
, what do you rebid here?
Q753
43
AQ3
KQ92
a) 1. I always shows the Major / bid up the line.
b) 1NT. I always bid NT if balanced
c) 1NT. This time the are no good, and it looks No-Trumpy. I would bid 1 with better Spades
If you always bid Majors “up the line” (style ‘a’ above) then the following auction denies four Spades:
1 1
1NT
This is a useful fact to know for your partnership. However, the following auction is a little ambiguous:
1 1
1
This shows four Spades, but could be balanced or unbalanced. This makes it hard for responder to preference Clubs or compete in Clubs later in the auction.
If you always bid NT with balanced hands (style ‘b’ above) then this auction handles all balanced hands, Spades or not:
1 1
1NT
There is a chance you’ll miss a Spade fit on a partscore board (not a game hand, enter Checkback!) However, partner knows that you are unbalanced on this auction:
1 1
1
Which makes it easier to preference Clubs, and helps bid constructively to the right game.
If you mix and match your rebidding style (style ‘c’ above), then partner can never be sure what you do and don’t have. You do get to tell partner about the most interesting feature of your hand though. Style-wise I reckon ‘a’ and ‘b’ are equally good, although different. Style ‘c’ makes it hard to quickly and accurately limit your hand type.
Simple Checkback:
Say the auction has begun:
(Partner) (You)
1 1
1NT ??
Now you might have only four Hearts, in which case there is no fit and it’s probably right to play No-Trumps at some level. If you have either five Hearts, or four Spades then you’d like to continue bidding to find a fit.
Enter Simple Checkback!
After the 1NT rebid, simple Checkback is a bid of 2 as an artificial enquiry. It simply asks opener for more information: 3 card support for responders Major, unbid 4 card Majors, 5 cards in their own suit. After Checkback, responder can
invite by raising to the three-level or bid game/slam as appropriate. If you play very simple bridge and don’t already
play Checkback, then maybe start here.
Two-Way Checkback
One disadvantage of Checkback is that you end up at the three-level after inviting game. A good solution is to play Two-Way Checkback. After the 1NT rebid here is the structure:
2* : Forces opener to bid 2*.
2* : Game Forcing Checkback.
2/2 : Weak hands, Natural.
After the 2 Puppet to 2, any bid by responder is now an invitation:
| (Partner) | (YOU) |
| 1 1NT 2 * |
1 2 * 2 Invitational with 5 Hearts |
Now all the invitations which get refused can stop at the two-level. If responder has a weak hand that wants to play in 2, he can puppet to 2 and then Pass.
After the 2 Checkback, opener just bids something sensible and keeps bidding until game is reached.
Here is an example:
| AK87 Q76 42 AJ92 |
QJ94 AK93 63 K84 |
| (Partner) | (YOU) |
| 1 1NT 2 (3s)3 |
1 2 * (Game Force) 2 (4 card suit) 4 |