32519, on 2013-May-15, 23:20, said:
What system do you play? By bidding ♠ first and then ♥ the natural conclusion would be that you have 5X♠ and 4X♥.
You are confusing two different auctions.
If partner opens 1C and you respond 1S, then bid 2H on the next round, you are showing 5 spades and 4 hearts (and a weak hand if partner's rebid was 1NT, say). That allows partner to pass 2H, or give preference to spades.
If you respond 1H on a 4-4, then partner can bid spades if he has them (unless you play a 1NT rebid is made on all balanced hands; then if responder is weak you miss your 4-4 fit anyway).
If you are weak and 4-4, you expect to pass partner's rebid.
The difference is that a 1M response to an opening bid is forcing; you bid your longest suit first to allow partner to pass your second suit or give preference.
After the auction starts 1C dbl 2C ? or 1C dbl P ? then, if you don't have enough to cue bid (to create a forcing auction), there are two differences: your 1-level or 2-level bids are non-forcing, and your partner has (in theory) shown support for both majors.
With partner implying support, you are now happy to bid both your 4-card suits if the opportunity arises. For example,
1C dbl P 1S;
2C P P 2H
this shows 4-4 in the majors. It allows partner to choose which major to play in at the 2-level.
If you bid 1H on the first round, and bid 2S on the next round then partner would have to give preference to 3H with, say, a 3-4-4-2 12-count which is not what you want.