One of the greatest weaknesses of less experienced players is being afraid to raise partner - one of the greatest weaknesses of the better player is imagining that every bid should be forcing. In this article we treat a common sequence that illustrates both of these failings.
You pick up Kxx x AQxx Kxxxx, and open 1♣. Partner responds 1♠. Too weak to reverse into diamonds, many would rebid 2♣ and quite likely miss an excellent spade fit. Much better is to raise to 2♠. Whilst this may lead to an uncomfortable 4-3 fit, far more often the 4-3 fit will be the right place to play, or partner will have five anyway.
In fact, most top players would raise if it had started 1♦ - 1♠ and they held Kxx x Kxxxx AQxx even though they could now comfortably bid their second suit. Many would also raise a 1♥ response with Kxxx Qxx x AKxxx, and on balanced hands with three card support.
Aside from the fact that you tend to land up in better fits by doing this, it also makes stronger hands easier to bid constructively. Kxx x AQxxx AQxx can bid 1♦ - 1♠ - 2♣ - 2♦ - 2♠, accurately showing the shape of the hand, and also conveying extra strength to partner, as with a weak hand you would simply have raised 1♠ to 2♠.
So how do you continue after 1♥ - 1♠ - 2♠? How do you investigate the right game? The key is to bear in mind that partner may only have three spades. With five spades it is easy - you can make a game try with 3♣ or 3♦, or a subtle game try by bidding 4♠.
With only four spades, you have to be a little more careful. If invitational, choose between 2NT and 3♥, both natural and non-forcing. If partner has a maximum he will choose between 4♠ if he has four, and 3NT or 4♥ if he has three. Note that 3♥ showed exactly three hearts and four spades, so it leaves partner well placed to select the right contract. Notice also that it is not forcing. If partner has a minimum and 3-5 in the majors, it clearly cannot be right for him to have to put back to the 4-3 spade fit.
With a game force and only four spades, choose between 3NT and 4♥, the latter when you have three card support (with only 3-4 in the majors partner should either open or rebid 1NT, so you are known to have a fit in one of the majors). With four spades partner will pull back to spades.
Raising on 3 card support: If this is a struggle to you, take comfort from the fact that with 6 of your first suit and 3 card support you can choose whether to raise partner or rebid your suit (though with six hearts it is almost certainly better to rebid 2♥).