[DrDouble]

I don't open 1NT with a 5 card major. Assuming responder bids stayman and receives a 2♦ response. The bids 2♥ & 2♠ r now unused. What r the problems of responder biding 2♥ or 2♥ to show 5 of the suit. If opener then does not have 3 of the major they respond 2NT. This seems 2 me to be a logical "extended stayman" system but I can't find anything on it on the Internet.

[awm]

This is the normal way to play without transfers. "Extended Stayman" means something different.

The main problem is when responder has five hearts and an invite, but opener bids 2♠ in response to stayman. Now you can't conveniently show your heart suit; you have to either bid 2NT (possibly missing 5-3 heart fit) or 3♥ (probably forcing). Also, you lose the ability to bid stayman on a weak hand with both majors.

[barmar]

Here are some more useful ways to use these bids:

1. 2♥ is Crawling Stayman, showing a weak hand with 4-4 majors. Opener passes with 3 ♥, corrects to 2♠ with 3 ♠, and you play in your 4-3 fit. Hopefully he didn't open 1NT with 2=2=5-4. I don't think 2♠ by responder has a meaning in this system.

2. 2♥ and 2♠ are natural, showing a weak hand with 5 in the bid major, 4 in the other. Responder was planning on passing if opener bid a major, but this allows finding at least a 5-2 fit.

3. Invitational Smolen. 2♥ and 2♠ show an invitational hand with 4 in the bid major, 5 in the other major. Opener then bids either the other major or NT at the cheapest level with a minimum, or game with a maximum. This is my personal favorite -- I'm usually happy to take a chance in 1NT with a weak responding hand.

[nigel_k]

I'd recommend:

2♥ as both majors weak. Opener either passes or bids 2♠.

2♠ as invitational, with five spades and four hearts. You could choose to bid this way without hearts allowing you to sometimes play 2♠ instead of 2NT (if it went 1NT-2♥-2♠-2NT). But if you do that you lose the ability to use 1NT-2♣-2♥-2♠ for another purpose.

You might also use the 1NT-2♣-2♦-2♠ sequence with 5-5 in the majors and game interest if you don't have any other way to show that hand.

[pirate22]

I think back to Acol days--extended stayman went

1n/t--p-- 2cl(stayman) pass
2d --p- 3d!(asking pard to bid his best 3 card major.
Before days of transfers--with the exception

2n/t pass--3d--(=get lost best contract,i have 5 hts weak/weak
regards

[P_Marlowe]

Hi,

just wanted to add, that "Crawling Stayman" also implies, that

1NT - 2D
2H - 2S

showes an inv. hand with 5 hearts and 4 spades, which would be the complement
to the beforehand mentioned seq.

1NT - 2C
2D - 2S

With kind regards
Marlowe