If partner opens one heart, what do I need to respond with one spade?

If my partner opens one heart, and I respond one spade, am I showing four or five spades?

In Standard American bidding (and 2/1 game forcing for that matter), after partner's 1H opening, 1S promises at least 4 spades. After 1H-1S, partner's mostly likely calls are 1NT (5332 shape with no more than 14 HCP), 2 of a minor (5-4 or better in the bid suits, may have anything short of a game force in terms of values), 2H (6+ hearts, probably less than 17 high card points), 2NT (18-19 HCP, 5332 shape), or some number of spades.

• 2H: This is a tough one. Probably 5 spades, a doubleton heart honor, and shortness in one of the minors. You're taking the position that playing 2H in a 5-2 fit is better than playing 1NT (if you had 3 hearts and a weak hand, you shouldn't have bothered to show spades).

• 2S: The 2S rebid shows a weak hand, usually with 6+ spades (though it could be an exceptionally weak hand with shortness somewhere and only 5 spades, e.g. Qxxxx x Kxx xxxx, which rates to take 0-1 tricks at NT but a few tricks with spades as trumps).

• 2NT: Invitational values, likely exactly 4 spades and 2 hearts.

• 3NT: Game forcing values, likely exactly 4 spades and 2 hearts.

• 3H: 3-card heart support, invitational values.

• pass: any weakish hand not covered above.

After 1H-1S-2m:

• Pass: A weak hand with 3- or 4-card support for the minor and usually a singleton or void in hearts.

• 2H: A weak hand, virtually guaranteed to have a heart doubleton (again, with 3-card support, why not raise hearts in the first place?)

• 2S: Shows 6 spades or better (or, more rarely, a weak 5-5 in spades and the unbid minor with a singleton heart). With other shapes and a weak hand, correct to 2H with a doubleton heart or pass partner's minor.

• 2NT: Balanced, invitational.

• 3m: 4-card support for the minor, invitational values.

• 3S: 6+ spades, invitational values

• The fourth suit at the cheapest level: forcing for one round, unable to make a natural bid at this point. Examples:

• Interested in 3NT but unable to stop the unbid minor.
• Interested in slam in one of partner's suits and thus unwilling to jump directly to game.

After 1H-1S-2H: - 2S: This shows a weak hand with 6 spades or better and likely a heart void; why else correct from partner's 6-card suit to yours?

• 2NT: Natural, invitational.

• 3m: Natural and game forcing.

• 3H: Invitational with 3 hearts.

Obviously, this doesn't cover all the bases, but it lays out some of the most common situations.

• Don't rebid 5-card suits unless as a positive statement of strength. You should know better @ruds, as your comments on Bridge are usually sensible. – Forget I was ever here Nov 12 '13 at 23:07
• Are you referring to 1H-1S-1NT-2S or 1H-1S-2m-2S? The first seems pretty sensible; without a doubleton spade, opener either has 6 hearts or a 4-card minor and so is not rebidding 1NT; therefore it is often reasonable to improve 1NT to 2S with a weak hand and 5 spades. As for a weak hand with 5=1=5=2 shape, 2D and 2NT are both stronger actions. Do you prefer a preference to 2S with that hand, or passing in a possible 4-2 fit? Anything you do could be wrong. – ruds Nov 13 '13 at 0:33
• Don't rebid a five ward suit with weakness. Partner will take you for 6, and is required to pass you with a void unless she is strong. Would you rather play in a 4-2 or a 5-0? Remember that partner's 1H opening, even playing 4-card majors, will be 5 cards long more than 70% of the time. – Forget I was ever here Nov 13 '13 at 5:34
• Rebidding a 5-card suit with a weak hand is the undeniable sign of a novice, who has yet to grasp the true fundamentals of bidding. Get over it. Read the literature on any decent web site, like Richard Pavlicek's (rpbridge.net/bbtc.htm), if you don't believe me. – Forget I was ever here Nov 13 '13 at 5:42
• You are simply wrong about correcting the 1NT rebid back you your 5-card suit; partner certainly doesn't have a void. After 1h-1s-2m when you hold 5-5 in spades and the other minor and a stiff heart, any call you take could be right or wrong, but I take comfort in the fact that partner's most likely shape is 5422, and so at MPs I bid the major. At imps, you haven't been doubled yet, so probably pass is the best call. – ruds Nov 13 '13 at 16:34