[jammen]

I have been away from bridge for decades and am curious about what is currently legal in tournament play. Would a bidding system based upon the board's colors be legal? Similar to the Woodson 2-way nt concept that was weak or strong depending upon vulnerability, this system would alter the meaning of many bids, not just nt, depending upon the specific vulnerability status when they are bid.

[hrothgar]

jammen, on 2015-February-28, 09:38, said:

I have been away from bridge for decades and am curious about what is currently legal in tournament play. Would a bidding system based upon the board's colors be legal? Similar to the Woodson 2-way nt concept that was weak or strong depending upon vulnerability, this system would alter the meaning of many bids, not just nt, depending upon the specific vulnerability status when they are bid.

This depends on jurisdiction.

Within the ACBL you're fine.
I believe that two system methods are much more tightly regulated under EBU laws.

[Cyberyeti]

hrothgar, on 2015-February-28, 10:47, said:

This depends on jurisdiction.

Within the ACBL you're fine.
I believe that two system methods are much more tightly regulated under EBU laws.

It used to be that you could do this only in high level competitions with sets of 8 boards or more in the EBU, we actually fell foul of it in the gold cup via a rule that wasn't meant to impinge on this, it was meant to stop you changing system to something ultra random when down in a teams match but was badly worded and got this too.

[helene_t]

It would surprise me if EBU had any issues with this, even in novice events, since variable notrump ranges were mainstream in the 50s in England and have been played at low-level club bridge (as well as by some decent players such as PhilKing ) by a significant minority ever since.

The Blue Book doesn't seem to mention it.

I know a decent pair who switches to something Lorenzo-like when they are behind in a team match.

[Jacki]

If you are playing in an ACBL game on BBO this chart shows you the legal bids:

http://www.acbl.org/...ntion-Chart.pdf

And this chart will help you know which bids should be alerted:

http://www.acbl.org/.../AlertChart.pdf

[barmar]

Jacki, on 2015-February-28, 15:33, said:

If you are playing in an ACBL game on BBO this chart shows you the legal bids:

The question wasn't whether a particular convention is legal, but whether it's legal to play a different system depending on vulnerability.

[blackshoe]

barmar, on 2015-February-28, 15:52, said:

The question wasn't whether a particular convention is legal, but whether it's legal to play a different system depending on vulnerability.

It is. 2/1 vul, Precision nvul, for example, is legal (assuming the individual system versions are legal - it's possible to put non-GCC legal methods in either system).

[campboy]

helene_t, on 2015-February-28, 15:30, said:

It would surprise me if EBU had any issues with this, even in novice events, since variable notrump ranges were mainstream in the 50s in England and have been played at low-level club bridge (as well as by some decent players such as PhilKing ) by a significant minority ever since.

The Blue Book doesn't seem to mention it.

This is covered in the Blue Book:

BB 5A5 said:

A partnership may play two basic systems at different positions or vulnerabilities only in Level 4 or Level 5 competitions, and only where rounds are of 7 boards or more. The partnership must display two system cards for each system, indicating the occasions when the different systems apply.

It is always permitted to vary certain parts of a system according to position and/or vulnerability. This includes, for example, variable NT openings and playing four or five card majors in different positions.

So the case OP was asking about is always fine, but changing between natural and strong club, say, would not be allowed in short-round events.

[jammen]

Thanks for the replies. I assumed that it would be legal as we already see wild preempts and two-suited bids being made at the expert level when white vs red. But I am surprised that I've seen nothing systemic being played that incorporates opening bids and overcalls.

[barmar]

jammen, on 2015-March-01, 07:48, said:

But I am surprised that I've seen nothing systemic being played that incorporates opening bids and overcalls.

Remembering all the details of one system is hard enough. Switching back and forth from one hand to the next is likely to be more confusing than it's worth.

[hrothgar]

jammen, on 2015-March-01, 07:48, said:

Thanks for the replies. I assumed that it would be legal as we already see wild preempts and two-suited bids being made at the expert level when white vs red. But I am surprised that I've seen nothing systemic being played that incorporates opening bids and overcalls.

Goldman and Soloway used to vary their system based on the opponents vulnerability.

They'd play 2/1 GF if the opps were NV and strong club if the opps were vulnerable