Source: Whenever you have a balance hand and the appropriate point count, open 1NT/2NT. There are absolutely no exceptions. Do not be distracted by a five-card major. Life will be much easier when you open 1NT with a five-card major and a balanced hand. You will not have a rebid problem and your partner will immediately know about your strength and balanced distribution. If you open your five-card major, partner will not know about your strength now, and there will be no way to tell him later! Bridge can be a very unforgiving game: Either you open 1NT, or can forget about showing your 15-17 HCP. Although many regard the above as heresy, please read on. What would you open with this hand? Spade Suit873 KJ865 AQ10 AQ If you open 1, your partner will often respond 1Spade Suit. The opponents are silent. It is time for your rebid; decide before continuing. Let’s round up the usual suspects, oops, I mean rebids:
  1.   Can you pass? Absolutely not! Partner’s 1Spade Suit response did not deny a good hand. It promised 6-16 points and was 100% forcing.
  1.   Can you rebid 1NT? No, this shows a balanced minimum; less than a 1NT opening. Obviously, a 1NT rebid misrepresents your strength.
  1.   Can you rebid 2? No. A 2 bid would promise a four-card suit. You are asking for trouble if you lie about your distribution
  1.  Can you raise to 2Spade Suit? No. This shows a minimum hand with good spade support. Partner’s response promises only a four-card suit.
  1.   Can you rebid 2NT? No. This shows more points than an opening 1NT bid. You would need about 19 points to make this bid.
Give up? You certainly do not need this aggravation – life is too short. Ignore your major and open 1NT. Spade Suit A10965  KQ7  Q7  AJ4 It is true that partner will not know that you have a five-card major when you open 1NT with hands like these. That is not the end of the world. (A convention called Puppet Stayman allows responder to discover if opener has a five-card major after opening 1NT.) It will be beneficial for you to declare a notrump contract. You would prefer to play last at trick one so that the lead does not come through your honors. Here is a recap:
  1.  Should you still open 1NT of the major is strong? yes, Yes, YES.
  1.   Is this true regardless of which major is involved? yes, Yes, YES.
  1.   Should you open 1NT with all balanced hands that include a five-card major and have the appropriate strength? yes, Yes, YES
Do I practice what I preach by always opening 1NT with five-card majors? Absolutely, positively, YES. I’ll conclude with two related examples. What would you do as dealer with this hand? Spade Suit KJ765  AJ10  AQ  KQJ                                   Open 2NT. Your right-hand opponent opens 1Spade Suit. What do you bid? Spade Suit KQ9  AJ765  AQ  875                                     Overcall 1NT.  Congratulations – you are on your way to becoming a practical nonstubborn bridge player.

            When opener shows a 5 card major:

West North East South
1 NT  P  2  P
2M P ?
2NT P 3 P
3M P ?
Call 2Spade Suit 2NT, 3 M 3NT, 4 M other M (3+) nonjump or  jump 4x 4NT 5 Meaning 4 spades (weak minor, no fit for M); I natural; I sign-off raise of M; slam try 5+ cards (does not deny fit); GF splinter raise; slam try quantitative Gerber
After interference: All doubles or redoubles by either player are for penalty. If responder’s L-H-O doubles 2 § or bids 2, the structure is unchanged (assuming no further enemy bid). Opener should make his normal rebid or pass, double or redouble. If responder rebids 2 ¨  it is to play (he would have passed 2 ¨). If either opponent bids 2 or higher (after the Stayman 2 § bid), the structure is off and the bidding reverts to a natural style. If opener cannot make his normal rebid, he should pass or double. If responder bids a major suit, he shows 4 cards in that suit (3 could be both majors after a 3 § or 3 overcall); this is invitational at 2Spade Suit or forcing at the 3 level. Opener may raise, return to notrump, or show the other major if appropriate.
West 1 NT P/D North P P East 2 ? South 2up
Call 2Spade Suit 2NT 3m 3M cue 3NT Meaning 4 spades; I invitational (ambiguous over 2Spade Suit) 5+ cards; GF 4 cards; GF asks for stopper sign-off