Some things you may not be aware of:

• You can open or overcall a weak two-bid with a five-card suit:

♠7 6 4 3
♥—
♦ A J 10 9 8
♣ J 10 6 5

This is a good candidate for 2 ♦ . You have a terrific suit with three honors and two great spot cards, plus two outside four-baggers and a void. This hand is a lot bigger than its six high-card points.

• You can open or overcall a weak three-bid with a six-card suit:

♠ 5
♥5 4 3
♦ A J 10 9 8 7
♣ Q J 10

There’s no downside to 3 ♦ . So any time you want to pre-empt, understand that making a weak two-bid with a six-card suit, or a weak three-bid with a seven-bagger, is a guideline, not a rule.

The most important concern is suit quality, but don’t overlook shape.

• Here’s an auction that’s often misunderstood. With South dealing ,the bidding proceeds as follows:

South.         West.         North.          East
1♣               Pass          1♠                 Pass
1NT            Pass          2♥                 All Pass!

Notwithstanding North’s new-suit rebid, 2 ♥ is not forcing. North’s auction suggests a 5-4 or 5-5 pattern in the majors and 6-10 HCP.

Well, suppose North has game-going strength with power in the majors:

♠ A K J 10 6
♥A J 10 6
♦5 4
♣ 4 3

This is a good time for checkback Stayman:

South.         West.         North.         East
1♣               Pass          1 ♠              Pass
1NT            Pass2♣ *

*Forcing bid that says nothing about clubs.

With three spades or four hearts, opener will answer in that suit. Holding both three spades and four hearts, South should bid 2 ♥. If there’s no fit in either major, North-South will eventually wind up in 3NT.

How about a 5-5 opening hand? Some will respond 1♠ , then jump to 3 ♥ . That’s O.K., but to be consistent with checkback Stayman:

♠A K J 10 6
♥A J 10 6 5
♦5
♣ 4 3

South          West          North          East
1 ♣              Pass          1 ♠               Pass
1NT            Pass          2♣ *

*Still artificial.

If South sees no major-suit fit, North can rebid hearts to show five of them. If there’s still no major-suit fit, 3NT will doubtless be the best contract.

Finally, here’s an auction where North is looking for a heart fit:

♠ A K J
♥A J 10 9 6
♦5 4 3
♣ 4 3

South          West          North          East
1♣               Pass          1 ♥              Pass
1NT            Pass          2♦ *

*Artificial bid that says nothing about diamonds (2 ♣ would be a simple raise).

With four hearts, South will bid 2 ♥ and North will raise to game, Otherwise North-South will play in 3NT.

There are some esoteric bids in checkback Stayman that will wait for another column. For the present, beware of responding 1♠ and then rebidding 2 ♥, unless you have modest values.

The Bridge Club of Martha’s Vineyard will kick off its 2018 season on Saturday, June 23 at the Tisbury Senior Center. Registration will begin at 9 a.m. and play at 9:30.