[Stephen Tu]

Don't have a link. GIB had something along the lines of Axxxx Kxx KQx xx, and bids 1s-2c-2s instead of 1s-2c-2nt. At a practice table it wants to bid 2S even with 8xxxx AKJ AQx xx. I kind of suspect that the rule for 2nt is never triggered, it always bids 2S on this and never 2nt.
2S on this auction is supposed to be fairly frequently six card suit; if balanced it should have an unstopped red suit.
Addendum: This seems to extend to other sequences both 1s/1h openers. 12-14, 5M332, it is always rebidding 2M regardless of stoppers/suit quality.

[virgosrock]

Stephen Tu, on 2018-July-22, 13:44, said:

Don't have a link. GIB had something along the lines of Axxxx Kxx KQx xx, and bids 1s-2c-2s instead of 1s-2c-2nt. At a practice table it wants to bid 2S even with 8xxxx AKJ AQx xx. I kind of suspect that the rule for 2nt is never triggered, it always bids 2S on this and never 2nt.
2S on this auction is supposed to be fairly frequently six card suit; if balanced it should have an unstopped red suit.
Addendum: This seems to extend to other sequences both 1s/1h openers. 12-14, 5M332, it is always rebidding 2M regardless of stoppers/suit quality.

Maybe, just maybe, wants partner to play 3 NT in such cases? who knows.

[pescetom]

Another case in which it could legitimately rebid the 5-card suit rather than 2NT is when it has a second suit which cannot be shown at 2-level and it lacks the extra strength to show it at 3-level.
But yes, it certainly prefers to rebid the major.