Source: 
Suppose that you are playing a 15-17 1NT and Partner opens 1NT. You hold any one of the following hands:
A. 
A43 
9 
KJT43 
QT65
B. 9 A43 KJT4 QT652
C. — KJ9 QT654 KQ543
In all three cases you are short in a major, have three cards in the other major, and have the values for game. But which game?
– 3NT will be a silly contract if the defense starts out by rattling off 5 or 6 winners in your short major.
– 5 of a minor may well be the ideal spot if Opener does not have our short major stopped (and two stoppers may well be necessary).
– 4 of a major (in the 4-3 fit) may well be the magic contract. All of the above hands are well-suited to playing in a 4-3 fit, with the ruffs coming in the short hand.
The Basics
So, what’s the solution? Yes, it’s the 1345 Gadget, we are calling it that until some kind reader tells us who is the author of this useful device. Here’s how it works:
– 1NT 3 shows Heart shortness (singleton or void), exactly three Spades, and 9 or 10 cards in the minors (usually 5-4 or 4-5 or 5-5)
– 1NT 3 shows Spade shortness, exactly three Hearts, and 9 or 10 cards in the minors.
An Example
| J 5 3 K Q 10 6 A 9 7 A Q 9 |
||
| A K 8 4 7 4 Q J 10 J 8 5 4 |
Q 9 7 6 2 9 5 3 2 8 4 10 6 |
|
| 10 A J 8 K 6 5 3 2 K 7 3 2 |
||
North is the Dealer, and many pairs will no doubt bid 1NT-3NT, and be down one on the obvious Spade lead. But the Gadget can come to the rescue here! North opens 1NT, South bids 3 (three Hearts and Spade shortness), and North has an obvious 4 bid. Sure, it’s a 4-3 fit, but the Spade ruffs can be taken in the short hand, and there are 11 tricks to be had with careful play.
Game-Forcing or Not?
Using the Gadget, can the bidding stop in 4 or 4? Perhaps you should allow for that possibility (though some don’t). That being so, after the auction has started 1NT 3, here are our suggested rebids for Opener:
– 3NT is a hand with a good Spade holding (probably two stoppers).
– 4 shows four (or five) Hearts.
– 4 and 4 show a preference for a minor-suit contract and can be passed if Responder is minimum (or has a “slow” hand).
– 5 or 5 are better versions of the aforementioned.
– 4 (Responder’s short major) show a really good hand in one or both of the minors, and are intended to encourage slam if Responder is so inclined. For a 4 bid, Opener needs to be rich in controls, without Spade wastage, maybe something like: J53, K6, AQT7, AQ97. As you can see, this fine specimen makes 6 or 6 a fine contract.
Two More Auctions
| Opener | Responder | |
Opener | Responder |
| 1NT | 3 |
1NT | 3 |
|
| 4 |
4NT | 4NT |
In both cases, we suggest that the 4NT bid says “pick-a-minor”.