When you have a long, strong major suit -- one that will definitely be trump -- there is an equivalent "shade card" for bids to match the strength of your hand. Color preferences are a matter of taste; fortunately, the major-suit shade card is pretty much standard.
To find the right shade, you must consider high-card strength and playing strength. For an example, let's use this hand from a recent Wydaho online game:
♠ AKJT8432 ♥ K ♦ 76 ♣ AQ
POP QUIZ: How many tricks is that spade suit worth?
ANSWER: Eight tricks. If partner has the queen, yay! If partner has three or more spades, yay! And otherwise, the queen might still be singleton or doubleton. Feel free to do the probability calculations, or just go with your gut feel that things will probably work out. Bottom line: You have an 87% chance for eight tricks, and a miniscule chance of only six tricks with this suit.
Okay, we have eight spade tricks. Add one-and-a-half tricks in clubs (partner has the king, or the finesse works, or an opening club lead), and a half-trick in hearts (partner has the ace or queen, or the ace is on our right and isn't played to the first round). That's ten playing tricks. You definitely want to be in game; slam is a distinct possibility!
How many ways can you open with a long strong major? We'll use spades for this discussion, but the same applies to a heart suit. You intend to unequivocally set the trump suit.
Shading from weakest to strongest:
-
Open 4 in first, second, or third seat. This shows 6 or 7 tricks (not
vulnerable) to 7 or 8 tricks (vulnerable). Most important, this denies an
opening hand. Partner will restrain her enthusiasm accordingly.
Example: ♠ KQJTxxxx ♥ xx ♦ xx ♣ x - Open 1, then rebid 4. This shows a full opening
hand, but denies enough strength for a 2 ♣ opener. Thus a
hand in the range of 11-15 HCP and about 7 or 8 playing tricks. Given your
shortness in other three suits, it seems quite unlikely that 1 ♠ will be passed
out.
Example: ♠ KQJTxxxx ♥ Kx ♦ Kx ♣ x - If your partnership plays the Namyats convention, open 4 minor showing 8 to
8.5 tricks in the corresponding major with some potential for slam if partner has useful outside
cards.
Example: ♠ AKJTxxx ♥ Kx ♦ KQ ♣ xx - Open 4 in fourth seat. This is not a weak preempt. You intend to get a plus
score; otherwise you could have passed the hand out, or bid only two or three spades. The bid shows about 8.5 or
9 playing tricks and at most a poor 15 HCP; you can count on partner to have one trick for you somewhere.
This bid denies slam interest. Even if partner has a
maximum for her Pass, she won't make a move at this point.
Example: ♠ KQJTxxxx ♥ Ax ♦ Kx ♣ x - Open 2 ♣, then rebid 4. This shows a bare minimum 2 ♣ opener, at least 14 HCP with long
spades and a hand worth about nine tricks. The message here is that partner should not pursue slam without three likely honor tricks. You have completely described your hand; it's up to partner to make any further move. (Regular partnerships should have an agreement on whether 8.5 tricks is enough for a 2 ♣ opening.)
Example: ♠ AKQTxxxx ♥ KQ ♦ xx ♣ x - Open 2 ♣, then rebid 3. This sets trump and asks partner to start cuebidding aces (or controls, per agreement) up the line. It shows a hand that is worth ten or more tricks, with at least 14 HCP. The key message is "spades are trump, show me controls." Show me the money, partner! You are the captain in this auction.
Example: ♠ AKJT8432 ♥ K ♦ xx ♣ AQ
Note what's missing here: There is no "open 2 ♣, then rebid two" option. When you are absolutely sure about the trump suit and don't care about finding a secondary fit, don't let partner blab about her hand to the opponents. Take charge, set the trump suit, and if slam is in the picture get busy finding out about controls in the side suits.
THE PRINCIPLE: With a one-suited hand, the playing strength of the hand -- how many tricks can you expect -- is at least as important as the number of high-card points. A 2 ♣ opener may contain as little as 14 HCP if it is within one trick of game against normal splits. Using this shade card for single-major hands, partner will have a good idea of the strength of your hand and can proceed appropriately. It's a partnership game!
BONUS MINUTE:
The ACBL Convention Charts allow a very strong artificial 2♣ opening that contains:
i. at least 20 HCP; or
ii. at least 14 HCP and is within one trick of game assuming suits break evenly among the other hands; or
iii. at least 5 Control Points and is within one trick of game assuming suits break evenly among the other hands.