HardVector, on 2022-August-13, 16:52, said:
I'm willing to bet that a XX forcing opener to bid 2h followed by 3c is forcing.
GIB never redoubles, the basic bot will bid a non-forcing 3
♣ even with an ace extra (while the advanced robot would just bash out 4
♥ and hope for the best).
GIB has a set of rules telling it how all of the continuations are defined after partner accepts the transfer with 2
♥ (and separate rules after a superaccept). This section doesn't include any rules for what to do if partner *passes* the transfer (despite the fact North has its own rule saying pass with 2 hearts, accept with 3 hearts).
So as with most competitive auctions, it falls back to a set of default rules that have nothing to do with transfers. There is a rule which says in general auctions like this, a new suit at the 3 level shows game forcing values. However, it has another rule that says if you're forced to bid and have no fit, a cheap new suit doesn't show anything. It combines the two, making the club bid but unable to promise any points.
Often fixing robot bugs is difficult because a slight change can break a bunch of other sequences. This one would be pretty easy to fix by adding a few new rules for continuations after this double that promise strength, after which default rules for later bids will work fine.