[AyunuS]

http://tinyurl.com/7c5ktvu

I don't see why it'd bid 3♦. The bid says 1-♥ so if I did only have 6♥ and at least 3♦ I probably would have left it there. I had already shown 6♥ and it has 2♥ so why didn't it just bid hearts?

[Bbradley62]

Also: why doesn't North bid 1NT over 1♠, and shouldn't East's 1NT say something about his heart holding?

[barmar]

The 3♦ bid came from simulations. The book bid is Pass, but in all the hands this ended the auction, and sticking in a bid that shows some values pushed the opponents higher or allowed NS to find a good contract.

North didn't bid 1NT on the first round because it didn't have opener's clubs stopped.

Opener's 1NT rebid doesn't care about stoppers in the overcall suit. I guess whoever wrote that rule believed in "stoppers are for wimps". Maybe at the 1 level it's not so important when your side has about half the points or more.

[Stephen Tu]

That explains bidding over passing, but it doesn't really explain 3d instead of 3h. Shouldn't 3h also accomplish getting to a good contract and/or push opps higher? To me it suggests 3h is poorly defined, maybe too encouraging to South, (or maybe not encouraging enough?). And/or South's upper limit is too high, so it thinks game is more likely than it actually is. Plus 3d is poorly defined, at 4+ diamonds, which suggest South corrects to 3h semi-automatically which removes the downside of 3d vs. 3h, whereas humans would assume 6+ diamonds and pass routinely as South.

[Bbradley62]

barmar, on 2012-May-10, 13:01, said:

North didn't bid 1NT on the first round because it didn't have opener's clubs stopped.

Opener's 1NT rebid doesn't care about stoppers in the overcall suit. I guess whoever wrote that rule believed in "stoppers are for wimps". Maybe at the 1 level it's not so important when your side has about half the points or more.

I guess the same programmer didn't write these two provisions :-)

I would like to suggest that following (1X)-1Y-(1Z) it is standard for a 1NT bid to show a stopper in Z, but not necessarily in the minor suit X, and that GIB should adopt this approach. I also think rebidding 1NT without opp's stop is silly when you have a perfectly rebiddable suit.

[barmar]

Bbradley62, on 2012-May-10, 17:25, said:

I guess the same programmer didn't write these two provisions :-)

It's very clear that the rulebase grew by accretion from a number of sources. And the way it's written makes it difficult to ensure consistency.

[barmar]

Stephen Tu, on 2012-May-10, 14:44, said:

That explains bidding over passing, but it doesn't really explain 3d instead of 3h. Shouldn't 3h also accomplish getting to a good contract and/or push opps higher? To me it suggests 3h is poorly defined, maybe too encouraging to South, (or maybe not encouraging enough?). And/or South's upper limit is too high, so it thinks game is more likely than it actually is. Plus 3d is poorly defined, at 4+ diamonds, which suggest South corrects to 3h semi-automatically which removes the downside of 3d vs. 3h, whereas humans would assume 6+ diamonds and pass routinely as South.

The problem is that 3♥ isn't encouraging enough: it shows 3-8 points, and North is too strong for that. So it bids a new suit to show a better hand.

[Bbradley62]

What would have been required for North to bid 3♥ directly over 2♥?

[Stephen Tu]

So:
- decrease upper limit for south's 2h (17 total points? 18?)
- have north raise to 3h directly over 2h, why passing here, if think too strong for 3h later? I'd be OK with north raising to 3h on this hand. If it wants to go low that's fine too, but once you go low there can't be game try later, it has to stick with it.
- 3d still has to be defined as 6+ diamonds. Then South passes this, then North realizes that risk of being in a stupid contract is worse than being slightly underbid and chooses 3h.
Don't know why 3d considered better hand than 3h anyway. That's just because poor definition of 3d, probably because not defined and falling back to some default rule.

[barmar]

Bbradley62, on 2012-May-11, 13:15, said:

What would have been required for North to bid 3♥ directly over 2♥?

It shows: 2+ H; 10+ HCP; 11 total points

There are a number of rules that generate the bid, and they each use different criteria, so it's hard to tell what the actual minimum requirement is.

[Bbradley62]

barmar, on 2012-May-11, 13:27, said:

Bbradley62, on 2012-May-11, 13:15, said:

What would have been required for North to bid 3♥ directly over 2♥?

It shows: 2+ H; 10+ HCP; 11 total points

North seems pretty unlikely to have 10+ HCP; 11 total points after passing over 1♠.

[barmar]

Bbradley62, on 2012-May-11, 13:31, said:

North seems pretty unlikely to have 10+ HCP; 11 total points after passing over 1♠.

True. The tool I use warns that the meaning contradicts something that has been shown earlier.

There are lots of rules like this. They exist to explain human bids, or to allow for simulations to find bids. You can't expect total consistency across all the rules if you also want the flexibility to apply judgement.

[Stephen Tu]

2+h is pretty unlikely (it should show exactly 2), but I don't think 10+ HCP is all that crazy, especially if you like to have spade stopper to bid NT. Personally I am not wild about bidding NT 4th chair in live forcing auctions since I like to overcall very aggressively at the one level and encourage my partners to do so as well, so don't want to step in when frequently outgunned, just defend when no clear fit. So I'd often be stuck with a fair hand and only 2 cd support when responder bids, would often pass and try to judge what to do later. You can have something like xxx Kx AQJx xxxx and not really have any great call. I'll raise my partner's 2 level overcalls on honor doubleton in a pinch, but like it less on their 1 level overcalls.

With 2h you are often stuck.

But the main thing I think is we want 3d better defined so GIB doesn't pull weird stuff out of its virtual posterior, and bids 3h as a mild underbid instead. Now on this particular auction having passed first, one could argue that 6d is impossible since one could open weak 2, bid 2d over 1s, etc., and that 3d should be a good raise to 3h, but I don't think we should make GIB so fancy .

[Bbradley62]

So, North passing three times then bidding 3♥ only when pushed by 3♣ shows 3-8 total points, and North bidding 3♥ directly over 2♥ shows 11 total points, leaving a gap for hands with 9-10 total points. Can we split the difference and say that the direct raise shows 10-11 and the only-when-pushed raise shows 3-9? (Since I think the given hand should bid the direct 3♥, I'd prefer 9-11 and 3-8, but the primary point is to eliminate the gap.)

Since it's so unlikely that North would pass three times holding six diamonds and then bid 3♦ at his fourth chance, it seems reasonable to say that this 3♦ bid shows 5+D. If the rule were written to say it requires 6D, the bid would never be made.

Edit: But, hands with 5D and 11 total points would likely bid 2♦ directly over 1♠. Hmmm....

This post has been edited by Bbradley62: 2012-May-11, 15:16

[Stephen Tu]

Bbradley62, on 2012-May-11, 15:13, said:

Since it's so unlikely that North would pass three times holding six diamonds and then bid 3♦ at his fourth chance, it seems reasonable to say that this 3♦ bid shows 5+D. If the rule were written to say it requires 6D, the bid would never be made.

I'm perfectly OK with defining the bid so that it's never made by GIB, but defining it catering to weird people who do pass several times, so that GIB can field it later even though it contradicts previous passes.

I've certainly never passed twice then come back in with 3d on this type auction. In general groping with new suits when partner has already shown 6+ ought to show 6+ also.

Does GIB play snapdragon?