Posted 2008-November-07, 07:34
Welcome to the pleasure of playing in an international environment!
The problem with something even as simple as this question, is that various bridge playing communities have different standards.
There are a few things that everyone playing a natural-based system (SA, 2/1, SEF, Acol etc) will agree on:
your hand g) With 5-5 in two suits, always respond in the higher suit (what you do on the next round depends on your strength and partner's rebid)
your hand e) With game forcing values, respond in your longer suit (so if you think this is a game force, respond 1D)
and (not shown)
With 5-spades and a 4-card minor, respond 1S
Once you get beyond these two points, it becomes a matter of style. Any beginner's bridge book you buy will tell you how to bid these hands, it's just they won't all say the same thing. If you all wanted to do was (e.g.) play standard French, we could give you a nice easy answer.
Like everyone else, I could just give you some rules, but I prefer to explain the logic behind it. The way to work out the right answer, is to think about opener's choice of opening bid, and opener's choice of rebid, bearing in mind that i) you would like to find any fit if you have one, but more importantly (ii) you would prefer not to miss a 4-4 major suit fit.
There are three styles of response:
1. "Up-the-line": with 4-4 or 4-5 in spades and diamonds, respond 1D
2. "Longest suit first": with 4-4 respond 1S, with 4-5 respond 1D
3. "Major first": respond 1S unless you have game forcing values
i) If you are playing a real 4-card major system, so a 1-minor opening is either an unbalanced hand or does not have a 4-card major, respond 1D. If partner does have a 4-card major he will bid it now, and you will not miss a fit.
ii) If you are playing a style where opener will always rebid a 4-card major if he has one, you can respond 1D. This (I believe) is the original standard american approach. Some SA texts say you should go for 'longest suit first'
iii) If you are playing a style where opener will always either open or rebid in NT with a balanced hand, you have to respond 1S, even with longer diamonds, unless you have a good hand, otherwise you might play in 1NT when you have a 4-4 spade fit available. This is the style called 'Walsh'.
You might point out a logical fallacy with option (3): if you have a strong enough hand to bid again over a 1NT rebid by opener, why not respond 1D and then look for a major suit fit over a 1NT rebid? This is a very good point, and so some people (including me) play that you respond 1S unless you have at least game-invitational values. However, that does seem to be a minority approach to life.