[hrothgar]

awm, on Oct 24 2006, 09:10 PM, said:

Seems like bridgebrowser might be a better tool than double-dummy solvers to evaluate the forcing 1NT response. A major issue is that while the "best two-suit partial" is often superior to 1NT, it's not clear how likely we are to find that partial after the forcing 1NT response. If opener bids 1♠ and responder is 1552 or 1435 with opener rebidding the shorter minor, it's anyone's guess where our best two-level spot might happen to be. In addition, 2/1 bidders are more often forced to take false preferences (i.e. bidding 2♠ after 1♠-1NT-2♣ when holding four clubs and two spades) which could easily be wrong (say opener has 5♠+5♣). In any case I'd recommend:

Look at hands where opener is 5(332) with 12-14 hcp and responder has 6-9 hcp with 0-2♠. Compare results from people who played the hand in 1NT versus those who played in 2♣ or above. Most likely it will be important to control for lehmans or the like, because 2/1 has become a defacto "expert standard" whereas many beginners play NF notrumps. Of course, this misses out on the hands where NF notrumpers win because they know openers 2m rebid promised four (as we're only comparing the results on the hands where NF notrumpers pass 1NT and forcing notrumps bid) but it still should give a reasonable picture.

Here's one other issue that might complicate the analysis:

There are a number of different response styles to a forcing NT. For example, the version of Polish Club that I originally learned uses a forcing NT response. However, the auction 1M - 1N - 2♦ promises 4+ Diamonds, while the 2♣ rebid only promised a doubleton. (I hadn't seen this before. I suspect that this innovation was inspired by the rest of this Polish CLoub variant, where a 1♦ opening promises 4+ Diamonds and a 1♣ opening could be based on a doubleton)

Personally, if I were going to study this I'd use a script. I think that the rules set for scrambling auctions is simple enough that you can produce some reasonable results.

[cherdano]

For me, the difference between an optional double and a takeout double is that you are afraid to make an optional double with a singleton in trumps, because partner will very often leave it in when they will make. I.e. it promises a lot more defense than a takeout double.
OTOH, when I make a takeout double, I can blame partner for the -730

Arend

[benlessard]

Quote

NF, opener never bids a minor on 3 (this is assuming 15-17 bal is opened 1N).

In standard this is a very common misunderstanding.

The 2M rebid is showing a minimum 6 carder hand. therefore with extra and a shapely 6 carder the correct rebid is 2m





With this 6331 the correct rebid is 2m.


AKJ
Kxxxxx
AQx
x


1H--1nt

the correct bid according to most expert is 2d not 2H and i really hope nobody bid 3h with this.


Partner will most of the time give preference with 2 and if hes got a stiff heart you will be happy stopping low.

The problematics hands are (MP) where partner got 5 D and 2H with a weakish hand where hew will pass 2d instead of correcting. or when he got 3136 3145 shape.

But notice that in IMPs this is a no-brainer

[helene_t]

I agree with Frances and several others that "semi-forcing" is a silly term. If responder is expected to keep the auction alive with 100% of his possible holdings, the situations is forcing. If he's expected to keep it alive with 99.999% of his possible holdings, the situation is non-forcing. There's no need for some term in between. Simple semantics, you don't need to know anything about bridge to understand this.

But I'm not so sure that "optional" s equally silly. A dbl gives partner some information on the basis of which he can decide to take it out or to leave it in. Surely, if partner has denied length in the opponents' suit and your double could easily be based on a void, a low-level double is 100% take-out, while a double on interference over partner's preempt is 100% penalty in many partnerships. But there's plenty of doubles which partner is expected to take out with appr. 50% (or 30%, or 70%.....) of his possible holdings.

It could be that the term "optional" is ill-defined, bad language, or that "optional" doubles (or whatever you call them) are over-rated. Consider the situation
1NT-(2♠)-dbl
Suppose your agreement is that the double suggests 3+ spades and that opener will normally leave it in with 3 spades. Some would call that agreement "optional double" but I think it's better to say something more specific. Say "suggests 3+spades" if that's what you mean.

[mike777]

"I agree with Frances and several others that "semi-forcing" is a silly term. If responder is expected to keep the auction alive with 100% of his possible holdings, the situations is forcing. If he's expected to keep it alive with 99.999% of his possible holdings, the situation is non-forcing. There's no need for some term in between. Simple semantics, you don't need to know anything about bridge to understand this."


Endless debate on this term of semiforcing...but assuming this means something.....then a bid that is 99.999 forcing is semiforcing and 99.998 is nonforcing? Yes semantics means something so semiforcing means something ok.....not the same as forcing or nonforcing but something different ok...Semantics!

think of the terms action and reaction...we would think reaction can only happen after action ...but this may not be true....reaction may happen before action....

In other words effect may occur before....wierd......

[benlessard]

I like the term "optionnal"

because it suggest the term "option" for your partner.

To a beginner i tell them its a take-out that he can pass if he doesnt want to bid or that its a penalty X that he can pull with shapes