[rhm]

Without special agreements consider

New suit bids of a potentially unlimited responder as forcing, with possible exceptions if opener has rebid 1NT.
New suit bids of opener without reverse as non forcing, if responder has responded at the one-level.
Otherwise consider new suit bids by opener as forcing.

Rainer Herrmann

[Vampyr]

Zelandakh, on 2014-February-26, 03:32, said:

That depends on which book you read!

I am pretty sure that the OP was asking about actual current practice, not about what material is in books.

[gordontd]

Zelandakh, on 2014-February-26, 03:32, said:

That depends on which book you read! The first place I came across this idea was a book from the master series in the eary 80s. It effectively forces 2/1 responses to be slightly stronger and therefore distributes the hands more economically between the available calls and this benefit is as true of Acol in Engliand (where I played it on occasion) as of other systems that use this or similar mechanisms.

There was a time (about 20 years ago) when 2/1 responses had been strengthened in Acol and some pairs (but still a small minority as I recall) played 2/1s as forcing to 2NT. I have never seen it in a book (though I don't doubt you when you say you have) and I haven't knowingly encountered this for quite some time. The only person with whom I ever played it suggested we abandon it a few years ago.

[Zelandakh]

Vampyr, on 2014-February-26, 04:41, said:

I am pretty sure that the OP was asking about actual current practice, not about what material is in books.

Generally things that appear in books have some basis on what is done in practise. As an example:-

the hog, on 2014-February-25, 23:31, said:

I disagree. 2/1 has been forcing to 2NT in Acol played in Australia for the last 30 years.

I think I made it quite clear that there are many different agreements possible here and that these affect the forcing nature of some calls. As I wrote in my original post, Acol is a broad church. You might be making the classic English mistake here of thinking that only a particular version of Acol can be considered genuine. Gordon is probably quite right that I am quite old-fashioned in my interpretation of Acol. My theoretical thinking moved on from Acol some time ago and I cannot imagine myself making another a big effort here when I found the 2/1 strengthening a plus in the past.

[gordontd]

Zelandakh, on 2014-February-26, 06:57, said:

My theoretical thinking moved on from Acol some time ago and I cannot imagine myself making another a big effort here when I found the 2/1 strengthening a plus in the past.

I think most players found that a plus, and it has remained in the modernised system with it's attendant forcing 2NT rebid and forcing new-suit rebids. It's just the forcing to 2NT thing that doesn't seem to have survived.

[jmcilkley]

So what about this?
1c opened, overcall of 1s, responder doubles, otheropp passes. Now is 2d a reverse? Maybe the double just shows 4 hearts and 8+ points and does not promise also diamonds. In that case the 2d redid must be a reverse so forcing while 2h is not!

[gwnn]

jmcilkley, on 2014-February-26, 08:52, said:

So what about this?
1c opened, overcall of 1s, responder doubles, otheropp passes. Now is 2d a reverse? Maybe the double just shows 4 hearts and 8+ points and does not promise also diamonds. In that case the 2d redid must be a reverse so forcing while 2h is not!

http://www.bridgebas...egative-double/
http://www.bridgebas...egative-double/
http://www.bridgebas...-play-this-one/
http://www.bridgebas...a-good-partner/
http://www.bridgebas...-many-controls/
http://www.bridgebas...-not-a-reverse/

(I got the list from: http://www.bridgebas...__1#entry728007)

Yikes, the last thread was started by you!