A Bidding Secret by Mike Lawrence. Source: ACBL Bulletin October 2010.
The more bridge you play, especially as you play in better fields, the more conventions you will run into. You may not choose to use some of these conventions, but It is a good Idea to Know what your opponents are doing.
One of these conventions is the Jacoby 2NT response to one of a mayor, e.g: 1
-Pass-2NT.
Many players use the 2NT bid to show a balanced hand with four- or 5ve-card support with game-forcing values. They have complex methods to continue the bidding from this point. Opener, for example, can show if he has a singleton. If opener is balanced, he can show that he has a minimum, an Invitational hand or a hand with slam potential
We aren’t going to explore Jacoby 2NT in this article. I want to tell you one of the little secrets that no one ever writes about. Do you recall hearing your partner bid 1
and the next player bidding 3
? If you recall such an event, you know that you were on shaky ground for the rest of the bidding.
Perhaps you got a terrible result when they preempted.
Here is the secret for the day. Almost any auction you are involved in can be disrupted by an opponent’s bid. This is true when you open with a one bid, and even lNT and strong 2 are subject to serious annoyances when they compete.
For maximum benefit, you should probably use this bidding trick only when not vulnerable. In our examples, your left-hand opponent has opened 1, your partner has passed and RHO has bid 2NT – a game forcing spade raise. Assume they are vulnerable and you are not.
43 KQJ85 
874 948
I suggest you bid 3 with this. This is a traditional pass and it comes with a lot of credentials. You have four tricks at best and might have only three. You know their side has at least 25 HP and may have more. If someone doubles you, you can expect to go down around 1100, maybe more. That is a lousy score unless they can bid and make a slam.
Why is 3 a good bid? There are two big reasons. The first reason for bidding 3 can be found in the introduction to the Jacoby 2NT bid. He describes his shape and values so that responder knows when a slam is posible or not posible. Opener needs all of his bids to do these things. If you bid 3 , you make a mess of their bidding. Unless they are incredibly sophisticated, they won’t be able to use their Jacoby 2NT tools and will have to make some guesses, which are not as good as precise tools.
They may choose to double, but given they have at least nine spades and know they can make 4 or even a slam, they will focus on finding a slam if one exists or at least getting 620 in a 4 contract. Remember, I said you should not do this except when non-vulnerable. If you bid 3, they know that setting you three tricks will be worth only 500, which is less than the value of their game.
The second reason for bidding 3. Is that if you escape undoubled, it means that they are playing in a spade contract and your partner will be on lead. You dont have to guess what suit he will start with. You will gain a lot at good boards using this tactic, and you will get a lot of satisfaction seeing your opponents fuming when you make one of these bids.
Be aware that there are some important points to consider. Your partner has to be astute about this idea and he has to have a sense of humor. If you bid 3 on the example hand, it is possible for your partner to have an 8, 9 or even 10 HP. If he takes you seriously, he may bid something or perhaps double them. This is a very bad idea. All your Partner has to do is consider that their side has most of the points and lots of trumps. Your partner should realize you are bidding on a good suit and little else. He should do nothing after your bid unless he has an absolutely magnificent hand with a lot of hearts and a lot of distribution. This really is an eflective tool. Try it!