HSBC

Friday, February 21, 2014

Play of the Hand Summary

General strategy of playing is: set up tricks early, take tricks late.

How to set up tricks, and how to know when to switch from setting up to taking is beyond the scope of this guide. This just points out some general conventions and guidelines.

2nd hand low

When your RHO leads, and you can't win the trick, it is rarely correct to play anything other than a low card

3rd hand high

When you partner leads and you can play a higher card than what has already been played, it is rarely correct for you to not play a high card in the suit.

Don't Lead Unsupported High Cards

It is almost never correct to lead a high card when you don't have the one right below it, and there are higher ones still out there. e,g, if you K53 of a suit, and the A hasn't been played, don't lead the K!

Defense

Sequence conventions

When leading from a sequence (e.g. QJT), lead the top of the sequence (e.g. the Q). When playing from a sequence, when you haven't led, play the bottom of the sequence (e.g. the T) Exception - HSBC leads K when holding the AK.

When following low to a suit

Give count. With an odd number of cards remaining play your lowest. With an even number play something higher. (note - sometimes it is correct to not do this, if your second lowest card is too high. Use your judgement. 2nd note - this is the HSBC convention, other players do things differently)

Lead through strength

If dummy is to your left, it is typically better to lead suits dummy has high cards in, than suits dummy only has low cards in. (i.e. you are trying to finesse dummy, not your partner).

Lead up to weakness

If dummy is to your right, it is typically better to lead suits dummy doesn't have high cards in. (i.e. you are trying to finesse declarer, not your partner).

Lead partner's suit

Unless you have a good reason to do otherwise lead partner's suit. (suit they've indicated via the bidding, or by their previous lead). It used to be said that the only reason to not lead partner's suit was if you were void in it, and even that wasn't a great reason. While the truth isn't this extreme, this is an important rule.

Don't lead opponent's suit

When in doubt, lead your best suit. (partially because that tells partner what to lead when they get in).

Don't change suits without a reason. When defense keeps switching what suit they lead, this almost always helps out declarer.

NT specific

Opening lead

Lead your side's suit, not the opponent's suits. I.e. you want to shy away from leading a suit the opps have bid, and you really want to lead a suit your partner has bid. (See rule above about leading partner's suit).

Outside of that, lead your longest suit.

Once you've picked your suit:

If you have a 3+ card sequence lead the top of the sequence. (e.g. Q from QJT53)

If you have 4+ cards in the suit, lead 4th best.

If you have 3 cards, lead 3rd best

If you have only 2, lead your highest.

Exception to above (only in NT), if you are leading from a 3 or 4 card suit where your highest card is the 9 or lower, lead your highest card, not your lowest.

Trump specific

Rule #1 - Don't underlead an ace! Doing so risks the wrath of the bridge gods, who may commit you to an eternity of hands where your finesses always fail and the trump always split 5-0. (doesn't apply if you are leading the trump suit)

Rule #2 - Don't lead an ace.

Just don't lead a suit where you have the Ace and not the King. If you feel you must break one of the above rules - break rule 2.

Lead partner's suit. (but try not to break the above rules).

Usually don't lead the opponent's (non-trump) suits.

If you have a suit with AK, lead the K. This is will often be your best opening lead, because you get to maintain control, and get to see dummy before your next action.

When to lead trump on defense is beyond the scope of this guide. Don't be afraid to do it, if you think you have a good reason to do so.

Declarer

When the opening lead is made, make a plan. Even if dummy has a singleton in the suit led, don't call for it until you've made a plan. Making a plan up front, makes it easier to count the suits you need to count, and to make the right play. In general, after making this plan, follow through with it, unless something unexpected happens. i.e. think more up front, so you can save time later.

No Trump

Count your winners. Do you have enough to make your contract? If not, how can you promote extra winners?

The general strategy in NT is to try and set up a long suit, so that the opponents run out and your small cards in the suit are good. Unless you are worried that the opponents can take too many tricks right away, set up your long suits before winning tricks.

Try to not play your stoppers in the opponents suit. For example if you have

A53 opposite 72

in the suit the opponents lead, you almost always want to duck the first 2 rounds of the suit and not win your ace until the 3rd round. This allows one of the opponents to potentially also run out of the suit, and therefore not be able to lead it if they get in.

Trump

Count your losers. (usually from the perspective of the hand with the longer trump). If you have too many losers, think of ways to get rid of losers. There are two main ways:

Set up a long suit - just like in NT.

Trump losers in the hand that is shorter in trump. (trumping in the hand that is long doesn't usually gain you tricks, since those trump were going to win anyway. It can be useful transportation, sometimes)

If you don't need your trump for something else, DRAW TRUMP! Don't carelessly win a couple side aces first. It'd be a real shame if that ace you were counting on got trumped.

Obviously, don't draw trump (or at least too many), if you are planning on trumping losers. How many trump you are going to draw right away should be part of your initial plan you make before playing to the first trick.

Bidding Summary

This is a summary of the HSBC variant of the Standard American system. It doesn't cover everything, and I probably skip over some things. So if you have any questions, please ask them.

Goal 1 - Major game. 8+ card fit and 26 (25?) points.

Goal 2 - 3N. No major fit and 26 (25?) points

Goal 3 - partscore - best suit (or NT) at cheapest level.

Goal 4 - slam (rarely.) 33+ points and an 8+ card fit - any suit. (Preferably 9+ cards) 37+ points for a grand slam. A good fit and the right distribution can lower these point count dramatically, but if you aren't sure, only look for slam if you think it is reasonable that your side could have 33+ points.

Note - there is no goal of bidding game in a minor. While it is occasionally right to bid a minor game, from a simplification stand point, you can just say you never want to do this.

Opening bids

2C - 22+ points

2N - 20-21 and balanced

1N - 15-17 and balanced

Other 1 level openings:

Major opening promises 5 cards.

Minor opening promises 3. (though partner can raise with only 4 if stuck for a bid).

Overcall promises 5+ card (both majors and minors).

Always try to find a major fit, even if you already know about a minor fit. (in competition you may violate this rule) i.e. if you have 5 diamonds and 4 hearts and your partner opens 1D, you should bid 1H, not 2D. You can always bid diamonds later, if partner doesn't support the hearts.

Responding

Supporting partner, promises 8 card fit. Raise to 2 level shows weak hand (6-10), raise to 3 level shows invitational hand (10-12). Raise to 4 level shows weak hand (5-8?) and good distribution (usually 5 card support for a major, 6 for a minor) plus a side singleton or void.

Bidding a new suit typically promises 4. New suit at the 2 level promises 10+ points.

New suit by responder is forcing, unless it is at the 1 level and responder is a passed hand.

Jump shift (e.g. bidding 2S after partner opens 1H) Shows a *really* good hand (typically 18+ points) and a good suit (at least 5 cards). Neither partner may pass below game, and you can't let the opponents play in an undoubled contract.

Rebidding

Rebidding a suit you've already bid almost always shows at least 6. Note, this means that there isn't really a way to show 5 cards (in a minor if you are opener, in anything if you are responder). This actually still works out most of the time.

Bidding a new suit is forcing, unless you are opener and the bid is less than a reverse.

Bidding 1N after a 1 of a suit opener limits your hand. As opener it shows a minimum opener. As responder it shows a minimum response. (6-10)

Competition

When both sides are competing it is usually more important to find the right fit than to bid game. With a good fit you can be more aggressive about bidding than you would without competition. The longer the fit, the more aggressive you can be.

Don't forget about double. If you are ever in a situation where it isn't obvious what you should bid, think if double might be right.

When both sides are bidding remember the rule "The 3 and 5 levels are for the opponents." For example, your side is bidding clubs, and they are bidding hearts.

1H 2C 2H 3C

3H P P 4C

The 4C bid is probably a mistake. You might encourage them to bid 4H and make a game they wouldn't have bid. Or maybe they'll double you and set you a bunch. Maybe they would've gotten set in 3H and instead you get set in 4C.

Double

Double is almost always some form of takeout. (Takeout/Negative/Responsive)

Remember that you have to bid even with 0 points, when partner makes a takeout double. e.g.

1H X P ?

Since you could have as few as 0 points, if you actually have some strength (say 8+ points) you need to let partner know by doing something stronger than just bidding a suit at the cheapest level. (Jump, bid NT, cue bid the opponent's suit)

It is penalty if your side has an agreed upon suit. Some examples:

1H P 3H 3S

4H 4S X P

This is penalty, since you already know what suit you want to play in.

2H 3C X P

This is penalty. When you preempt, you have set the suit, so later doubles are penalty.

It is also penalty, if takeout just doesn't make sense, based on the bidding. Example:

1H P 3H P

4H X

This is penalty, because if this hand wanted to do a takeout double they would have done it the first time.

Pretty much every other double is takeout of some form.

Note - if your partner makes a takeout double, you are always allowed to leave it in. But make sure you are doing it intentionally, not because you don't know what else to do. I.e. if the bid is below game (2D, 3S, etc.) you should be *very* confident you will set the contract to leave the double in. If the bid is game (4H, 5C, etc.), it is much more likely that you can leave it in. If partner is doubling at this high of a level they have a strong hand. Given this, if you think your side can make, you should bid, but if you are not, it is probably safer to pass.

Note - in a team game, you should only double someone into game if you are confident you can set the contract at least *2* tricks. You can be a little more aggressive with other contracts but you still want to be sure.

doubling into game: 2H doubled is game (since 4H is game) but 1S or 2D doubled is not game (since 2S or 4D is not game

1N responses

When you open 1N, even though you have the strength, your partner is the captain. You've already described your hands and they make the decisions.

When partner opens 1N, there are two questions you want answered. "Do we have enough points for game?" "Do we have a major fit?"

Responses to 1N (make sure you have these memorized)

2C - Stayman. Asks partner to bid a 4 card major, or bid 2D with no 4 card major. Promises at least 8 points.

2D - Transfer. Tells partner to bid hearts. Promises at least 5 hearts and between 0 and 40 points.

2H - Transfer. Tells partner to bid spades. Promises at least 5 spades and between 0 and 40 points.

If you have a weak hand (less than 8 points) and a 5+ card major, please transfer and don't pass! The weaker your hand, the more important this rule is!

2N - Invitational (8-9 points)

3 of suit - don't make this bid, unless you have had a very specific conversation with your partner about what it means and you are 100% sure they will know what you mean.

3N - to play

4D - Transfer. Tells partner to bid hearts. Promises at least 6 hearts and game values

4H - Transfer. Tells partner to bid spades. Promises at least 6 spades and game values

4N - invitational to slam. This is *NOT* ace asking

If the opponents interfere over the 1N bid, but before you bid, here are my recommendations:

If they double - bid as if they hadn't bid.

If they bid 2C - same, but double if you want to bid Stayman.

Anything else:

2N / 3N / 4N bids mean the same thing as before (but should show a stopper)

2 of a suit - I want to play it here. The 1N opener should pass!

3 of a major - 5 card suit, 1N opener should either bid 3N or 4 of the major.

4D or 4H (if you still had the option of bidding 3 of a major) - transfer bids

4H or 4S (if you didn't have the option of bidding 3 of a major) - to play.

X - takeout. With a stopper the 1N bidder should probably consider bidding NT.
Bidding the opponents suit - Strong and forcing.

Any other bids - make at your own peril, but presumably natural.

Preempts

If you open with a preempt (2 level, 3 level, 4 level) and partner:

Raises your suit (to any level) - you should always pass

Passes - you should always pass

Bids game (in your suit, 3N, or a different suit (not the opponent's suit)) - you should always pass.

Remember this. When you've preempted, you have described your hand and put your partner in control. Let your partner decide how high to preempt.

The only time you should bid again is if partner bids a new suit below game (natural and forcing) or if partner bids 2N. (asking for a feature. It doesn't come up often, so if you don't know what it means, don't worry about it, unless you're comfortable with everything else in this document.)

When partner preempts

If you think you can make game - bid it.

If you have a strong hand, but aren't sure about game, either bid 2N (asking for a feature) or bid your own 5 card suit, naturally.
You *cannot* invite in partners suit. Raising their bid to 3 is *NOT* invitational. They *will* pass.

If your hand isn't strong enough for a game, a good rule of thumb is to bid to the number of combined trump you have. So if partner opens 2H, and you have 2 hearts, you have an 8 card fit, so it is safe to be at the level where you need 8 tricks, i.e. 2H. So don't raise. With 3 card support, raise partner to 3H. With 4 card support you can raise to 4H.

Also - when raising partner's preempt, it is almost always right to do it right away - raise as high as you are willing to at your first bid, and then pass if the opponents bid any higher.

2C Openers

Responding

With a good 5+ card suit (2 of top 3 honors) and 8+ points, you can bid your suit. (2H/2S/3C/3D). With a strong balanced hand, you can bid 2N. Any of these bids are game forcing, and it is likely that you will end up in slam.

With almost all hands you want to respond 2D.

Opener now describes her hand. 2N shows a balanced hand with 22-24 points. (too strong for 2N, too weak to open 3N). 3N shows a balanced hand with 28+ points. (opening 3N shows 25-27) Systems are on, just as if they had opened NT (but with a different point range, of course)

Any other bid is natural and forcing. After an auction that starts:

2C 2D

?(not no trump)

all bids below game are forcing except a raise of a naturally bid suit.

2C 2D

2H 3H not forcing

2C 2D

2H 2S

3H not forcing

2C 2D

2H 2S

3C 3S not forcing

All other bids (below game) are forcing. Even if you have 0 points!!!! Remember, as responder, you only need about 3-4 points to force to game. Partner might be happy going to game even if you have 0, so respect this rule.

Other Conventions

You should really be comfortable with everything above here before playing the following conventions. And if you do want to play them, make sure you keep them straight. If you think you will get Michael's Cue Bid and Unusual No Trump mixed up - don't play them. It is better to not play a convention than to get it wrong. (and let partner know to not bid them.)

Michael's Cue Bid

Bidding the opponent's suit at your first opportunity, when neither you nor your partner has bid anything. Over a minor it shows 5-5 in the majors. Over a major it shows 5-5 in the other major and an undisclosed minor. (partner bids 2N to ask which minor). ex.

1H 2H P ? (shows spades and a minor)

Unusual NT

Jumping to 2N over the opponent's 1 level bid at your first opportunity, when neither you nor your partner has bid anything. Shows 5-5 in the two lower unbid suits. ex.

1H 2N P ? (shows clubs and diamonds)

Blackwood

A bid of 4N (when you aren't bidding NT naturally) asks for aces. 5C = 0 or 4, 5D = 1, etc. If your side has all 4 aces, you can ask for kings by next bidding 5N. (only if you bid 4N originally)

Note - over NT, 4N is "quantitative" i.e. invitational to slam, but not forcing.

Gerber

over NT, a *jump* to 4C is ace asking. 4D = 0 or 4, 4H = 1, etc. ex.

1N P 4C P

If there has been a bunch of bidding and then someone on your side bids 3N and partner bids 4C, this is natural and not Gerber. It is only ace asking if it was a jump to 4C over a natural NT bid.

Sunday, August 25, 2013

Analyze the Bidding

Part of being successful at the bidding or playing in bridge is understanding what is said at the table. The more information you can glean from everyone else's bidding the better position you'll be in to make the right decision.

Imagine the bidding sequence (opp's passing):

South North

2C 2S

3C 3H

3N 6C

6N pass

What can you tell about North and South's hands?

Here's what we learn one bid at a time.

2C - 22+ points or a hand that is within one trick of game (because of distribution).

2S - 8+ points, a good 5+ card spades suit headed by 2 of the top 3 honors. Also a hand that feels it is worth taking up bidding space to tell partner about his own suit before hearing her suit. (because he didn't bid 2D) Note, at this point the pair is in a game forcing auction, and has at least slam interest.

3C - opener's long suit. Presumably 5+ clubs. Says nothing about points.

3H - shows a two suited hand (spades and hearts), says nothing about points.

3N - This is a very descriptive hand. This game bid is not forcing. As such we know south has less than 3 spades (didn't support spades), less than 4 hearts (didn't support hearts), and doesn't have crazy distribution (didn't rebid a minor). Since she doesn't have crazy distribution, we know she has 22+ points. However, since we know she didn't make a forcing bid, she has at most about 24 points. (with more, she'd want to go to slam, knowing partner has 8+ points). So know we know south has 22-24 points, a balanced-ish hand probably with 5 spades.

6C - This is also descriptive. North is showing club support, so at least 3 clubs. So we know north has 5+ spades, 4+ hearts, and 3+ clubs. This only leaves one card we don't know about. We also know he has 11-12 points. With less, he wouldn't be comfortable going to slam, and with more he'd be looking to see if grand slam was available

6N - South has diamonds stopped (probably twice), and wants to play in the higher scoring contract.

As you can see, you can learn a lot from the bidding even without a lot of conventions. (only the first two bids were conventional, and only one wasn't natural.) The important thing to always remember is every bid is said in the context of what has already been said. And, unless forced, every bid should be either describing something new about the hand, or placing the hand in what is expected to be the final contract.

Saturday, April 13, 2013

Support Partner or Bid Your Suit?

Some of the challenges in bridge are deciding what to do when you have no good options, and some are when you have multiple. Today I'm going to discuss one of the latter. What should you do when your partner opens one of a suit and you have both support for partner's suit and your own suit to bid? Should you support partner? Should you bid your own suit?

The answer is, like most, it depends. Rather than just give you rules to memorize, I will show you the logic behind the rules. Understanding the thought process will help you for those situations where none of the rules fit quite exactly, or to decide when to break the rules.

Goals

The most important thing to remember about Standard American bidding is that you are trying to find out if your side has game, in particular 4 of a major or 3NT. So the two questions you are trying to answer are, does your side have a combined 26 points? Does you side have an 8 card fit in a major? You want to find out the answer to these questions as quickly as possible.

All of the below situations assume that you have support for your partner's suit and have your own suit to bid.

When Your Partner Opens a Minor

If your partner opens a minor suit (1C or 1D) and you have support for that minor, and you also have a major, bid your major suit. Even if you only have 4 cards in your major and you have 5 or more cards in your partner's minor. Until you have ruled out game in the major, look for a major fit rather than a minor fit.

For example, if you have:

S 10 5

H K J 4 2

D A 8 6 4 3

C 4 3

and your partner opens 1D, you should bid 1H. Yes, diamonds is almost definitely your best fit, but you first need to explore to see if your side can make 4 hearts, which will probably be easier to make than 5 diamonds, if your partner has four card heart support for you. If your partner does anything other than support your hearts, you can now bid diamonds with a clear conscience.

When Your Partner Opens a Major

If your partner opens a major (1H or 1S) and you have support for that major and another suit, its a little bit more complicated. I'll break this down by point ranges.

0-5 Points

Pass. You know you have less than game, so don't encourage your partner. Of course, if the opponents enter the bidding, you may bid later, knowing you've already told your partner you have a weak hand. (This, of course, is also true if they had opened a minor.)

6-10 Points

Bid 2 of your partner's suit. Even if your other suit is really nice, support partner. Given your weakness, it increases the odds that the opponents will bid something. Now you are in a competitive auction, and your partner doesn't know about the fit, and so can't make an informed decision. And by the time the bidding gets around to you, the level might be too high for you to be comfortable bidding again.

S A Q 10 7 5

H 6 4 2

D 6 4 3

C 4 3

This is really important, so I'm going to repeat it. If you have a weak hand, the most important thing you can do, is to support your partner's major suit bid. On the above hand, if your partner opens 1H, bid 2H, not 1S.

10-12 Points

This is an in-between scenario. In some systems, like 2/1 (a popular system based on Standard American), it would depend on whether you have 4 card support for your partner's major or only 3. For the HSBC standard, I'm going to recommend going the simpler route of just bidding 3 of your partner's major. This bid shows your strength range and your support all at once. It's very descriptive, makes it hard for the opponents to enter the bidding, and hopefully gives your partner enough information to do the right thing.

13+ Points

With this strong hand, you already have both the questions answered. You know your side has 26+ points and you know your side has an 8 card major fit. Now you have the freedom to consider other options. Maybe your side has slam (6 or 7). Bid your suit and see what happens. A new suit by you is forcing, so you aren't worried about your partner passing. You can always bid 4 of your partner's major as your next bid, if nothing good comes about.

Friday, October 7, 2011

Responding to 1 of a Minor

When your partner opens 1 of a Minor, how should you respond? Remember your main goal is to find a "Golden Game", which is an 8 card major fit, and 26 points.

Here's how to think through your responses.

With Less Than 6 Points
If you have less than 6 points, you almost certainly don't have game, so just pass so the bidding doesn't get too high.

With a Major (6 or more points)
If you have at least 4 cards in a major bid it at the one level. If you have both majors, bid the longer one. If they are the same length:

With 4 each - bid 1H
With 5 or 6 each - bid 1S

Without a Major

With 6-10 Points
You want to let partner you have some points, but not too many. If your partner opened clubs, and you have diamonds (at least 4 of them), you can bid 1D. If you have support for your partner's minor (at least 4 cards, preferably 5 or more) you can bid 2 of your partner's suit. Otherwise bid 1NT.

Just like over a major:

Do not bid a new suit at the 2 level without at least 10 points!

With 10-12 Points
Again, if your partner opened clubs, and you have diamonds (at least 4 of them), you can bid 1D. If your partner opened diamonds, and you have clubs (at least 4 of them), you can bid 2C. If you don't have any other 4 card suit, you must have support for your partner's suit, so bid 3 of your partner's suit.

With 13+ Points
If you have a balanced hand, bid 2NT. If not, you can bid 1D with diamonds (if partner opened clubs), and 2C with clubs (if partner opened diamonds). If none of these apply, you can bid your partner's suit at the 4 level. (though, in this case it is usually better to lie, and bid one of your other suits at a low level, to keep the bidding low while you explore).

Examples
For all of the following examples, assume that your partner opened 1D.

K8532

43

987

642

With less than 6 points, just pass.

AK532

43

987

642

You have a major, so bid it: 1S.

AK53

T4

A9832

42

Even though you have support for diamonds, show your major first: bid 1S.

AJ987

5

43

AKQ65

You have two 5-card suits, bid the higher one: 1S.

AKJ9

AQ53

43

Q65

You have two 4-card suits, bid the cheaper one: 1H.

75

432

AK653

654

With no 4 card major, and diamond support, show your diamonds. Bid 2D.

Q54

KJ6

AJ765

43

With no 4 card major, and diamond support, show your diamonds and your points. Bid 3D.

AQ4

KJ6

AJ765

43

With no 4 card major, a balanced hand, and 13+ points, show your points and your distribution. Bid 2N.

754

43

64

AQ6532

Your longest suit is clubs, but since you have less than 10 points you can't bid them at the 2 level. With no suit to bid at the one level, bid 1NT.

Opening 1 of a Minor

Requirements for Opening 1 of a Minor
(clubs or diamonds)

13+ points
longest suit -or- no 5 card major

Other Considerations
If you have two 5-card suits (or 6 card suits) that are the same length, open the higher one. i.e. Prefer spades to hearts to diamonds to clubs.

If you have no 5-card major, and your minor suits are the same length, open 1 diamond if you are 4-4 in the minors, and open 1 club if you are 3-3 in the minors.

Examples
In all the examples the suits are ordered, from top to bottom, spades, hearts, diamonds, clubs. A number means a card with that number, A = ace, K = king, Q = queen, J = jack, and T = ten.

Q74

AT5

63

AK532 

With 5 clubs and 14 points (don't forget to count the 1 distribution point for the fifth club), open this 1C.

Q74

AT5

63

K7532 

With less than 13 points, just pass.

AK53

K74

KT43

63

You have 13 points, but you don't have a 5 card major, so open this one 1D.

53

9

AK532

AQ743

You have enough points to open, and two 5 card minors, so open the higher one: 1D.

532

96

AK53

AQ74

You have enough points to open, and two 4 card minors, so open the higher one: 1D.

9532

943

AK5

AQ7

You have enough points to open, and two 3 card minors, so open the lower one: 1C.

Q532

A784

AK5

AQ

You have enough points to open, but no 5 card major, so open the longer minor: 1D.

Friday, September 23, 2011

Responding to 1 of a Major

When your partner opens 1 of a Major, how should you respond? Remember your main goal is to find a "Golden Game", which is an 8 card major fit, and 26 points.

Here's how to think through your responses.

With Less Than 6 Points
If you have less than 6 points, you almost certainly don't have game, so just pass so the bidding doesn't get too high.

With Support
If you have at least 3 cards in your partner's major, you know you have an 8 card fit, so you have found a fit. Now your only question is how high to bid.

With 6-10 Points
You want to let partner you have some points, but not too many. Just bid 2 of your partner's suit.

With 10-12 Points
This is considered "invitational strength", since all it takes is for partner to have a little bit beyond a minimum opener for your side to have the 26 points required for game. Bid 3 of your partner's suit to invite to game.

With 13+ Points
You know that 4 of your partner's suit is almost certainly the best place to play. However, you don't have to go right there. Bid something else (2NT with a balanced hand, or a new suit, otherwise), and let your partner redescribe their hand with another bid. This may give you enough information to determine if you should bid slam.

Remember, in this situation, your partner doesn't know that you have the major fit yet. All of the possible bids you could make is beyond the scope of this post. If your next bid is 4 of the major, your partner will now know what you were doing.

Without Support
If you don't have support for your partner's major then you still have to find what suit is best for your partnership. In general, your best bid here is your longest suit, at the cheapest level that you can.

Suits of the same length
If you are have two suits that are the same length that you are choosing between, the rule is:

If the suits are 4-4, bid the cheapest suit. (i.e. whichever one comes soonest in the bidding sequence)
If the suits are 5-5 or 6-6 bid the highest suit. (i.e. prefer spades to hearts to diamonds to clubs)

Weak Hand
The caveat to the above rules is:

Do not bid a new suit at the 2 level without at least 10 points!

So, if you do not have a new 4 card or longer suit that you can bid at the 1 level, and you have less than 10 points, then you should bid 1NT.

Examples
For all of the following examples, assume that your partner opened 1H.

K8532

43

987

642

With less than 6 points, just pass.

AK532

43

987

642

You don't have enough hearts to support, so bid your longest suit: 1S.

AK532

643

98

642

You have support for your partner's hearts. Show that by bidding 2H.

AK53

43

A987

642

You have two 4-card suits. Since 1S is a cheaper bid than 2D, bid 1S.

AK53

T432

A98

42

You have support for hearts, and enough points to invite, bid 3H.

AJ987

5

43

AKQ65

You have two 5-card suits, bid the higher one: 1S.

7543

43

AK652

64

Your longest suit is diamonds, but since you have less than 10 points you can't bid them at the 2 level. Bid 1S since you have 4 of them.

A5432

KQ6

AJ76

4

You have support for hearts, and enough points to go to game. However, with this many points you don't have to go straight there. Just bid 1S for now. You can always bid 4H on your next bid.

754

43

AQ6532

64

Your longest suit is diamonds, but since you have less than 10 points you can't bid them at the 2 level. With no suit to bid at the one level, bid 1NT.