[gnasher]

 iviehoff, on 2012-September-26, 03:11, said:

I think this could get you in trouble unless you were careful. A course of conduct of doing this would become an implicit/concealed agreement.

It woudl become an agreement, certainly. There's no reason to assume it would become a concealed agreement.

[TimG]

 iviehoff, on 2012-September-26, 03:11, said:

I think this could get you in trouble unless you were careful. A course of conduct of doing this would become an implicit/concealed agreement.

I would be so careful as to disclose the agreement, not that I think that requires much care, just the normal way to play bridge.

[iviehoff]

 gnasher, on 2012-September-26, 07:06, said:

It woudl become an agreement, certainly. There's no reason to assume it would become a concealed agreement.

"Concealed agreement" would only come up if you were "psyching" the bid and partner was observed to be fielding it.

If on the other hand, you disclosed an agreement that you would sometimes choose to pass strongish flat hands (say 14-17 ish), although your convention card otherwise suggested you opened all 13+ hands, I suspect you would now be playing a HUM. Since it occurs before the opponents have made a call, it could not be justified on the grounds of being a defence to a HUM.

[Zelandakh]

Read 6.2 again ivie - the rules do not say anything about altering one's opening bids only after the opponents have called. They say "In preparing the defence against a HUM system, pairs using Green, Blue or Red systems are allowed to change their systems, including opening calls. Pairs using a HUM system are not allowed to change their opening calls." That certainly does not preclude passing on some hands that would have been opened playing against a non-HUM system.

[TimG]

 Zelandakh, on 2012-September-26, 08:23, said:

Read 6.2 again ivie - the rules do not say anything about altering one's opening bids only after the opponents have called. They say "In preparing the defence against a HUM system, pairs using Green, Blue or Red systems are allowed to change their systems, including opening calls. Pairs using a HUM system are not allowed to change their opening calls." That certainly does not preclude passing on some hands that would have been opened playing against a non-HUM system.

That "including opening calls" part makes the opening calls part of the defense and seems to be necessary in order to avoid the situation where a FP pair announces their system, the opponents announce "in that case we also play a FP", and then the original FP pair announce "in that case we don't play a FP", etc.

[mycroft]

...and that happens sometimes - I know I've read stories about the FP defence to FP in Australia before.

[bluejak]

 iviehoff, on 2012-September-26, 08:16, said:

"Concealed agreement" would only come up if you were "psyching" the bid and partner was observed to be fielding it.

While not relevant to this thread, as a general comment I believe this to be incorrect. Concealed agreements come up in MI cases.

[FrancesHinden]

TMorris hasn't said what the event is, but I'm not sure why everyone is assuming it's the Gold Cup. You can play HUMs in the premier league as well, and there are various non-nationally-run English events that allow any system to be played.

Anyway, as has already been observed, if your opponents play a HUM you can play any defence you like against it. That's true anywhere that I've ever seen such systems allowed.