

When your partner opens a strong 1NT and you have a very weak hand with both majors, if your goal is to find a good (or often the best) major to play in at the two-level without compromising your no-trump response structure, you should play “Garbage” Stayman, as shown here. Other less-efficient versions exist.
When you have a very weak hand with both majors, you normally can’t use Stayman, as you are required to have around 8 or more HCP to use it. However if your partnership decides to play Garbage Stayman, you can still bid 2C, asking if opener has a 4-card major and if he responds 2D, denying one, 2H now is Garbage Stayman – demanding opener chose between playing 2H or 2S. Playing Garbage Stayman opener must pass 2H or bid 2S and will always choose his longer major if he is 3-2.
Garbage Stayman can be used with a weak hand with 4-4 in the majors and with 5-4 in the majors but it’s best usage is when you are 5-5 in the majors (with any 6-5 or 6-6 in the majors, bidding and making game is a possibility, although some pessimists might still use Garbage Stayman).With 0-6 HCP and 5-5 in the majors, you should always use Garbage Stayman, as if partner responds 2D (denying a 4-card major) you will bid 2H, forcing him to chose between playing 2H or 2S.
If you have 0-6 HCP, one five-card major and one four-card major, you must use bidding judgment whether to transfer to your five-card major or use Garbage Stayman. Here are some good guidelines:
#1. If you have a “bad” five-card major and a “good” four-card major (both HCP and spots) and a weak hand, it is strongly recommended that you use Garbage Stayman. On the other hand, if you have a “good” five-card major and a “bad” four-card major, just transfer to your five-card major and pass.
#2. When both your 5-card and your 4-card major are basically equal in quality (HCP and spots), you want opener to have a clear choice after 1NT-2C-2D-2H. For this reason, you should pick one major to usually transfer to when you have 5-cards in that major (and four in the other) and use Garbage Stayman when you have five cards in the other major. While it may not be the universal choice, it is recommended that you transfer with five hearts and four spades and use Garbage Stayman with five spades and four hearts (when neither suit is significantly better than the other one), as this method yields slight theoretical advantages. Whether you choose spades to be the “default” major, as recommended, or hearts isn’t the most important thing. What is important is to have an agreement. Having either agreement allows opener, over 2H, with 3-3 in the majors to choose the major most prone to deliver a 5-3 fit. If partner almost always bids Garbage Stayman with five spades and four hearts, with 3-3 in the majors opener should always bid 2S over 2H, as that’s your best chance for a 5-3 fit and also gets the big hand to be the declarer.
If you have 0-6 HCP and you are 4-4 in the majors, this is where good bidding judgment and partnership agreements are necessary. Here’s what some experts do: There are experts who will routinely pass 1NT when they’re 4-4 with a weak hand. Some use Garbage Stayman when they have a singleton in a minor, some use Garbage Stayman with good texture in their suits or without a sure entry to be able to take a finesse, etc. and there are some experts that always use Garbage Stayman when they are 4-4 in the majors with a weak hand. About half the time opener will have a 4-card major and all will be well but when he doesn’t, you’ll at best wind up playing in a 4-3 fit, which may play better than 1NT – or may not.
Standard 2-Level Major Bidding Structure over 1NT: playing Garbage Stayman & with 2NT as artificial:
1NT: 2C-2D-2H: = Garbage Stayman. Opener
must pass or bid 2S (should
normally bid 2S with 3-3).
2C-2H-2S: = Shows four spades and invitational values.
2C-2H-2NT: = Denies four spades, shows invitational values.
2C-2D-2S: = Shows five
spades, four hearts and invitational values.
2D(transfer)-2H-2S:
= Shows five hearts, four spades and invitational values.
2D or 2H(transfer,
forcing 2H or 2S)-2NT:
= Shows five of the major and invitational values.