Posted 2018-April-25, 10:17
I'm not saying South is supposed to bid the grand either on this hand. I'm saying that it's very, very hard to specify every specific sequence where North should NOT show all key cards by bidding 5nt. If I have to choose between North making specious 5nt bids showing all key cards but never bidding grand, vs. North trying to be selective about it, I'd much rather they program it so that it just always shows all key cards if 13 is plausible. Because there are hands that are absolutely dying to see if all key cards are held, but North grabbed blackwood first, and I absolutely don't want to be at the mercy of North using its judgment about whether or not to confirm all key cards are held.
You don't lose anything by having North make 5nt asks when neither or North nor South can bid the grand with confidence. You bid the small, so what, you took some extra bids, it was a waste of time, but you didn't mess up your result? At least by forcing North to always show all keycards, you don't miss the grands where the human can infer 13 tricks. If you want to make North be selective about it, a ton of hands will fall through the cracks in the rules, because it's just really hard to come up with enough rules to cover all auctions, and for the computer to figure out that on this auction it should show but this other one it shouldn't bother.