[Bbradley62]

What in the world is 4♠?

---

I'm particularly puzzled that 3♠ is explained as 4S whereas 4♠ is explained as 4-S.

[Stephen Tu]

It got confused because it's only expecting 3nt or 4s from you over 3s as possibilities. 4h doesn't exist for it in theory, so it falls back to some kind of default interpretation which might include 4s. I guess it is trying to get to a potentially better fit. 4h shouldn't be bid, but I guess if it is it should have a limit of 2-3 spades.

[EricK]

Stephen Tu, on 2012-May-12, 00:40, said:

It got confused because it's only expecting 3nt or 4s from you over 3s as possibilities. 4h doesn't exist for it in theory, so it falls back to some kind of default interpretation which might include 4s. I guess it is trying to get to a potentially better fit. 4h shouldn't be bid, but I guess if it is it should have a limit of 2-3 spades.

If anything, it's the 3♠ which shouldn't be bid. I can't see the full description of 2NT, but does it deny 4♠? In any case, why does 3♠ promise exactly 4♥? How is he meant to bid a hand which is 45 in the majors?

[Stephen Tu]

2nt doesn't deny 4 spade for GIB or for most people these days. With GIB methods it bids 3s with 4-4 in the major, uses unbid minor to checkback with 45 in the majors (with which I'm currently debating Barry/Fred in that it doesn't seem to be able to find 4-4 fit when 5-3 in the first major is also available, which I think is non-std).