Posted 2016-January-06, 12:00
This is a well-known problem that has been referred to many times, but is, as yet, unaddressed. For some reason GIB does not recognize that the jump advance of the double showed invitational values, and treats the normal 3NT call as showing massive strength. We all hope this will be fixed in the long-awaited next GIB revision.
It would also be nice if GIB could recognize that the N hand had already shown its full values, and that if partner were that strong it would not sign off in 3NT.