Opening Bid: One Notrump - 15-16 HCP
Most players are comfortable with the 15-17 range, but forcing club systems frequently use a different point-count range for the opening bid of 1NT. A range of 14-16 is the most popular, but 13-15 is also often used. Usually the reason for this is to mitigate the problems caused by opening the Precision 1, which is the worst bid in bridge!
We use 15-16 points and agree that we seldom have a 4-card major, but never say never. (In the 80's there was a popular system called "Matchpoint Precision" that played 1NT without a four-card major. It's not a new idea.)
Why do we use only a 2-point range? Because it eliminates the need for responder to make an invitational bid, and improves the accuracy of responder's decisions. Responder can almost always decide whether to pass or bid higher when she knows her partner's point-count that closely.
A goal here is to eliminate the complexities involved with the responses to a standard 1NT call, which is generally defined as 15-17 HCP, and may have a either a 4-card or a 5-card major. Most players have poorly defined agreements, too, for hands that have a powerful minor and perhaps an outside void, especially when the long suit is clubs. How do you find a grand slam in clubs, if your partner opens 1NT and you have a hand similar to this one? (If you use Gerber, you might find that your partner has only one ace... The useful A, or the worthless A?)
Besides, what level of club bid would actually show a club suit?
There's a really big advantage to using only a 2-point range in other ways, as well. The main one is being able to respond in any of the four suits at the 2-level with the agreement that it is not forcing. The opener should pass any 2-level bid by her partner. How many other players can play in a contract of either 2 or 2 after a 1NT opening?
Any response at either the 2-level or the 3-level should show at least a 5-card suit.
All 3-level responses are natural and game forcing
Because we have only a 2-point range, we do not need to use a raise to 2NT as an invitational call. Instead, we can use the bid to show hands that hold 5-5 in either the majors or the minors. Responder should bid 2NT with such a hand, with these agreements:
Responder can also raise the opener's minor suit bid, going past 3NT, and indicating a possible slam interest.
If responder has the hand with 5-5 in the majors, she should correct to 3 and allow the opener to either raise or correct to spades.
Something simple - Redouble with 10+ points. It's our hand!
Some things do not change. A bid of 4 over an opening 1NT is standard Gerber.
This is a convention used by experts, but not much by club players. You can add it to your agreements or not. The problem with the agreement is that it's difficult to remember, especially since it occurs so infrequently. It's a very good agreement, though, if you can remember it.
You might prefer to Google it and find a more complete explanation of the agreement, but below is a short description:
If you bid anything at either the 2-level or the 3-level, is that a forcing call, or can your partner pass? Difficult question, eh?
The part of our agreement that applies to this version of notrump is this:
What's so difficult about that? Nothing. And it's easy to remember, too. But it begs the question, How do you bid if you simply want to compete and you want your partner to pass your 3-level bid?
If you bid 2NT, by agreement that forces the opener to rebid 3, which you might pass with a club suit and few points, or you might correct to a different suit at the 3-level, with the understanding that your bid is natural and non-forcing! (It's easy to forget that a response of 2NT is not a competitive raise.)