jdonn, on Mar 5 2008, 11:53 AM, said:
I think I'm a fairly smart person who understands the laws well.
And I'm totally confused...
This is definitely a confusing area, and despite a lot of effort the law is difficult to read. However, my understanding of what it means (and I think a careful reading will confirm this) is that you can change even a conventional insufficient bid to a different bid as long as the
insufficient bid doesn't give your partner any information that isn't included in the sufficient bid. So, to take a simple example - I play weak NT and open 1
♣ with all balanced hands in the 15-19 HCP range. Suppose that RHO opens 2
♠ and I "overcall" 1
♣. On it being pointed out to me that 1
♣ is insufficient, and after the law is carefully explained to me, I change my bid to 2NT, which shows a balanced hand of 16-18 or so HCP. My second bid is one that was included in the hands shown by the first bid but is
more precise, thus it is allowed - my partner doesn't have any information other than that provided by the 2NT bid.
On the other hand, suppose that I play 2-way Stayman over both 1NT and 2NT opening bids (OK, that's not something anyone plays, but it makes the point). Partner opens 2NT and I bid 2
♦ forcing to game and asking about Majors. I am not allowed to correct this to 3
♦ even though that also is forcing to game and asking about Majors because the original bid showed a better hand than the new bid and so partner knows something about my hand that is not included in the new bid.
The point is to be fair - did you ever get caught by the old rule when partner opened 2NT and you mistakenly responded 2
♣ Stayman and now had no way to avoid a penalty? Yet allowing you to correct 2
♣ to 3
♣ wouldn't damage the opponents and would get things back to "normal." Should it matter that the bid isn't just one level higher in the same strain? For example, I play transfer responses to 1
♣. A 1
♦ response shows 4 or more hearts and says nothing more about the hand. If the opponent overcalls 1
♦, my DBL substitutes for the 1
♦ bid. The set of hands in DBL is a little smaller than those in 1
♦ since I might respond 1
♦ on hands that would pass over 1
♣-(1
♦) but there are no hands with which I would DBL but
not bid 1
♦ in the uncontested auction. So there is no harm done by allowing me to DBl when the 1
♦ overcall is pointed out to me.
I hope that makes it clear. And I really do think that is what the law says, admittedly using more words in order to make sure it is complete. I admit my logic days are far behind me, so I can't easily discuss it in terms of sets and intersections and exclusions. But the point is that the new bid is allowed so long as the insufficient bid doesn't provide any information that is not provided by the new bid. So there have to be no hands that are included in the new bid and not in the insufficient one, since those hands would be excluded by the information provided by the insufficient bid. There can be hands that are included in the insufficient bid but not in the new bid, because then the insufficient bid doesn't clarify the new bid.