When the auction starts as follows:
|1 of a suit||Pass||Pass||??|
we try not to pass. As South, we are considered to be in the "balancing seat." That means, "if we pass, the auction is over." Usually, it is not right to sell out so easily without competing at least for the partscore.
Accordingly, the guidelines for bidding in this position are relaxed a bit. The general approach is to take action with a king less than you would have in the direct seat (which would have been North in the above auction). Since an overcall in direct seat usually contains at least 9 or so HCP, an overcall in the balancing seat can be made with as few as 6 HCP. A direct-seat takeout double is usually a hand worth 13 points--in balancing seat it can contain only 10 (counting distribution). Overcalling 1NT in direct seat shows 15-18, so in balancing seat it shows approximately 12-15. In summary, here are the balancing seat auctions:
|1 of a suit||Pass||Pass||Overcall = 6 + HCP, 5+ card suit|
|1 of a suit||Pass||Pass||Double = Takeout with approximately 10+ points counting distribution|
|1 of a suit||Pass||Pass||1NT=12-15 balanced (and a stopper(s) in the suit opened)|
After all of these balancing actions, the partner (North in the diagram) must tread lightly. He has to "subtract a king" in all of his follow-up actions (in other words, he needs more than usual to raise or look for game). After the 1NT balance, he should use Stayman and transfers.
What if the player in balancing seat has a regular 1NT opening (15-17) with the opponent's suit stopped? He is too strong for 1NT (12-15), so he must double and then bid notrump. Doubling followed by bidding (in balancing seat) shows a "big" hand in context. Not the usual 18+, but more like 15+.
You don't always want to balance if the opponents are about to play in 1-of-a-minor. Consider whether your partner is likely to have a hand that could match yours. Remember that partner could have overcalled in a major-suit, so you shouldn't always stretch. If opener is likely to have something like a 2NT rebid, they won't be very happy playing in 1 in a 4-2 fit.
Note: When it goes 1NT--P-P, it is also usually a good idea to balance. Again, the standards are relaxed. In this case, though, there is also the matter of which methods you and your partner play against 1NT opening bids.
Advanced note: Believe it or not, jumps in the balancing seat are not preemptive. It makes no sense to preempt if you can just pass to end the auction. Accordingly, a jump in balancing seat shows a good hand. A jump in a suit (such as 1-Pass-Pass-2) shows a good 6+ card suit and at least a full opening bid. A jump to 2NT in balancing seat is not the Unusual Notrump. It shows 19-21 balanced with a stopper(s) in the opponent's suit. So, 1-Pass-Pass-2NT is something like:
updated: October, 2020