[Bbradley62]

http://tinyurl.com/28th3mg

North's 2♠ bid is explained as "Limit major raise -- 4+H; 10+ total points".

I thought the term "limit raise" meant that the bid has an upper limit, whereas this bid appears to be unlimited.

What would a bid of 3♥ have shown instead of 2♠?

[ahydra]

That 2S looks like one of the forcing bids we humans are always looking to make but GIB never understands as forcing

besides, you landed in a decent enough place (just the diamond ruff gets you down).

ahydra

[barmar]

Just a guess, but maybe 3♥ would show a 6-card suit.

Artficial bids like this are often split-range, either limited or very strong. If partner tries to sign off and you bid on, it shows the strong range. But I have no idea if GIB plays this (I think Ari has mentioned in the past that this is hard to represent in its bidding database).

[Bbradley62]

And, why did West bid 2♣ instead of 1♠?

[manudude03]

I can only speculate, but Gib simulated that it had more clubs than spades and was seeking to play in its best fit. People overcall 1S more often with 5S+4C than overcall 2C with 5C+4S.