Bidding 1 NT as an overcall shows about 15-18(19) points, balanced(ish) hand with a stopper(s) in the suit opened.

Hand (i) is a classic 1 NT overcall – balanced 15-19 with a diamond stopper (third-round but that’s fine). Note that it’s far better to bid 1 NT than 2 ♣ – you’ll get to your most likely game (by far) of 3 NT much more easily. This is because 1 NT shows the strength of your hand whereas 2 ♣ does not (about 8-18).

With Hand (ii) you are stymied. You would have opened the bidding 1 NT, but now have no convenient bid. Double (for take-out) is too risky as you have insufficient spades. Just pass – you may have a chance to enter the auction later.

With Hand (iii) you might bid 1 NT – you satisfy all the criteria. However with such a tenuous diamond stopper – the ace will soon be forced out and then what? – and with four cards in both majors, I would certainly double. Most of the time you’ll locate a nice little 4-4 major fit.

The best policy when responding to a 1 NT overcall is to use the same system as you do over a 1 NT opener (Stayman and Transfers recommended). Because partner has shown at least 15 points, you’ll only need 10 for game.

Click to play this hand