1S : 1NT : 2H : 2NT = 3 spades invitation

[shep]

https://tinyurl.com/yyrrxhdr

 

I wonder how GIB shows an invitation without a major suit fit.

[shyams]

The 2♣ Drury promises a 3- or 4-card trump fit.

 

If I recall, the natural NT invitation (i.e. max hand for opening pass + balanced no ♠ fit) will directly bid 2NT over 1♠.

[zhasbeen]

https://tinyurl.com/yyrrxhdr

 

I wonder how GIB shows an invitation without a major suit fit.

 

This doesn't answer the "without a major suit fit" part of your question, but the hand you submitted is much too good for 2H rebid. I'd go with 3H, then run my cursor over the call and make sure it is forcing. If not I'd bid 4. I've had over a 1000 games of ACBL Daylong variety alone last 2 years, and still am never sure what Gib "thinks" I have. For the 2H rebid I'm 95% sure it's not forcing, which as about as sure as I can get with the Gibster.

 

To answer last part of your question, you need to give some examples. However, you could do some trial and error by taking the same step of hovering your cursor over the call to see what it says. That would be on my top tips list for anyone who doesn't have a lot of experience with Gib. I have taken the meaning of some of Gib's bids for granted and not followed this advice too many times. The result has been an unexpected and unpleasant surprise that was unnecessary.

 

Disclaimer: as most regulars know, Gib definitions are often wrong, but there is far more to be gained by checking what they say than not. The more you play the more you know when to be skeptical, and when not. However, occasional disasters are inevitable no matter what you do."Occasional" might be overly kind.