[Bbradley62]

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How is South, having jump-shifted, supposed to know whether to move over 4♥ if the bid really is unlimited in strength (6+ total points, per the description)?

[lycier]

 Bbradley62, on 2015-February-16, 16:55, said:

How is South, having jump-shifted, supposed to know whether to move over 4♥ if the bid really is unlimited in strength (6+ total points, per the description)?

If it is me,I may bid 3♥ with 9+TPs after reverse bid 2♠.
Gib have to be careful in this complicated hand.
1- I do think 2♠ is a reverse bid,IMO.It is not a jump-shift" bid which happens only in 3-level.
2- It involves a contract problem.
How to select a reverse contract?
1)-At BBF," A primer on reverse bidding " by mikeh is a good option.
2)- Ingberman convention is excellent.

[Stephen Tu]

lycier, in standard american this is termed a jump shift, not a reverse. Differences:
- reverse auctions show strong hand *without* jumping. Here there was a non-jump option of 1♠
- why it is called reverse is that the two suits are shown in the reverse of the economical order.
- jump shift auctions are forcing to game. Reverse auctions have a lower low bound for opener, and provide a mechanism to stop short of game on some continuations.

[Bbradley62]

 lycier, on 2015-February-16, 18:58, said:

1- I do think 2♠ is a reverse bid,IMO.It is not a jump-shift" bid which happens only in 3-level

 Stephen Tu, on 2015-February-16, 19:22, said:

lycier, in standard american this is termed a jump shift, not a reverse.

This is a matter of English language, not of "standard american", which could be misunderstood to mean a bidding system that GIB does not play. Note that GIB does include the words "jump shift" in his description. As Stephen explains, 1♦-1♠-2♥ would be a reverse, whereas the given auction is a jump shift because I jumped over 1♠ when making my second bid. I'm quite sure the sources you mentioned would agree with this definition.

[Bbradley62]

Now that we've got that cleared up, the 4♥ bid still needs to be defined better.

[lycier]

 Bbradley62, on 2015-February-16, 19:56, said:

Now that we've got that cleared up, the 4♥ bid still needs to be defined better.

No.
I disagree because this is not how to define 4♥.
The main problems are how to define rebidding at 3-level,including rebid-2N.( I like Ingberman convention.)
This is most critical problem.
I also think the hand you provide is really meaningful,very very good.

[Bbradley62]

So, first we need to know: How does GIB currently handle bidding after a jump shift?

Then, everyone can explain their better ideas.

[Stephen Tu]

 lycier, on 2015-February-16, 20:17, said:

No.
I disagree because this is not how to define 4♥.
The main problems are how to define rebidding at 3-level,including rebid-2N.( I like Ingberman convention.)
This is most critical problem.
I also think the hand you provide is really meaningful,very very good.

I think all BBradley is saying is that 4H should have an upper limit. Perhaps should be defined as something like 6-10 points or so. Opener should almost never be bidding over 4H anyway, so perhaps it doesn't matter much.

Most people do not play Ingberman or similar conventions over opener's strong jump shift. This is because JS is stronger than reverse, game forcing (roughly 19+ HCP instead of ~16/17+), and in theory there is no need for a weakness signal by responder in order to try & sign off in a 3 level partial. Responder can just bid naturally, everything forcing below 3nt, and then bid more later if warranted.

[lycier]

 Stephen Tu, on 2015-February-16, 22:46, said:

I think all BBradley is saying is that 4H should have an upper limit. Perhaps should be defined as something like 6-10 points or so. Opener should almost never be bidding over 4H anyway, so perhaps it doesn't matter much.

Most people do not play Ingberman or similar conventions over opener's strong jump shift. This is because JS is stronger than reverse, game forcing (roughly 19+ HCP instead of ~16/17+), and in theory there is no need for a weakness signal by responder in order to try & sign off in a 3 level partial. Responder can just bid naturally, everything forcing below 3nt, and then bid more later if warranted.

NO.NO.NO.
You made such a bad mistake.
Just now I am very lucky to get a evidence hand on reverse bid.

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Please look at 2N,it says " Artificial 2NT,any weak hand--- 4+♠,7-hcp,6-8TPs".
If 2nt is a artificial with any weak hand,I am sure that all of bids at 3-level must show 8+hcp,9+TPs with GF.
If you don't believe what I said,please request gorgi to tell us,ok?

[Stephen Tu]

1d-1s-2h is a reverse auction.

1d-1h-2s is a jump shift auction.

They are not the same thing!
The first does not create a GF. Therefore you need an artificialish 2nt bid to get out when you have a min and don't want to be in game with 16/17 opposite 6-7 or whatever.

The second DOES create a GF. Opener is promising a stronger hand than a reverse auction, 19+ HCP. You are in a GF. So you don't need a weakness signal, since you aren't ever passing anything below 3nt. Also, opener's range is narrower (since the floor is higher, and you are limited on top end by failure to open 2♣), so there's less need for these kind of range sorting bids for responder to know what to do, when you are dealing with an ~19-21 range for opener instead of a ~16-21 range. You are always in game, you aren't worrying about staying lower than game, and if responder is strong they can just do something appropriate after a fit is or isn't agreed and cue bid or RKC etc. if slam is in the picture.

Also, on the reverse auction you actually posted, I think GIB should switch to the more common style where 2s is bid with wide range of hands, F1, but not promising any additional strength, and 2nt is potentially weak hand but DENY 5 card spades. So that you don't get too high and can play 3♦ when opener is like 3451 min or some such rather than 4-3 spade fit.

[Bbradley62]

 Stephen Tu, on 2015-February-16, 22:46, said:

I think all BBradley is saying is that 4H should have an upper limit. Perhaps should be defined as something like 6-10 points or so. Opener should almost never be bidding over 4H anyway, so perhaps it doesn't matter much.

This. But, while the human may know (with the strong hand) that pass is almost required over 4♥, if it is not coded internally then there may be times when GIB has the strong hand and thinks that his partner is unlimited and he continues.

[georgi]

Thanks for reporting.

I think it's improved now as shows 6-10TP once you close the game.