palabreur

Computers choose plays by simulating outcomes. The other two times, the simulation suggested that covering was correct. At your table, the simulation came up with the opposite conclusion. Or did you phrase your question poorly? :)

Are you just trolling? There's no way to know I have a club loser specifically... though I suppose from GIB's perspective, a club loser is more likely than either of the other side suits. But surely not certain enough to bid the grand.

The main problem here is the awful 2♣ response. 3NT is far superior.

So in a robot race tourney, I hold ♠A ♥AKQJT9754 ♦A ♣A5 which I like the look of. I almost never open 2♣ playing these, but what else can you do, other than get into a blackwood sequence and find out about the ♣K (hooray for specific kings, a convention GIB plays). So the auction proceeds, opponents silent: 2♣ 2♦ 2♥* 3♥ 4NT 5♣** 5NT 6♥*** 6NT 7♥**** all pass * 2♥ was probably unwise, 3♥ would be better (assuming it shows solid hearts); but given how GIB treats 4NT (keycard for last bid suit) I think I can always get away with it. ** zero keycards (no surprise) *** zero kings (oh well, let's play the rock-solid 6NT) **** ZOMFG! :) So I guess my "bug report" is, please, dear whatever deity you want, please stop GIB from "correcting" out of 6NT. (Note: karma was kind; partner dropped with a stiff ♣Q and 3 hearts.)

Not quite. Those hands are balanced, so they use a jump shift only if they are 18-19 hcp. 1C-2D shows either 18-19 bal, a strong hand with diamonds, or a strong hand with diamonds and clubs. Why do we do this? So we can immediately start thinking about slam, without needing to jump later on. 1C-2D, now you know to evaluate your hand for slam. 18-19 balanced is relatively rare, so probably evaluate your hand based on a club or diamond slam.