Old York, on May 15 2009, 06:22 PM, said:
In a perfect world, oppo would be given full disclosure about these treatments. In practice, many partnership agreements are left undisclosed. The negative inferences can be very subtle, easy for opener to understand, but impossible for oppo
The use of 2
♠ is often semi-psychic, and opener fields the psych by failing to bid 4
♥. Is this 100% ethical?
These special treatments and continuations work best if oppo are uninformed and confused. This worries me greatly, especially if oppo are less experienced
Using Multi against advanced, experienced oppo is good fun, and can easily gain or lose, so it is perfectly fair and ethical. Using Multi against inexperienced oppo is almost always bound to gain an unfair advantage. Using Multi against BI with special partnership tweaks just seems to convey a win-at-all-costs attitude
I wish I could see a way out without banning
Tony
Edit: I will kib some Benelux tournies... I am genuinely interested in learning

Methinks that you are barking up the wrong tree
1. I agree that different partnerships play radically different response structures over a multi 2
♦ opening. Some players prefer a style in which a 2
♠ response shows (Hearts + values). Some players prefer a style in which a 2
♠ response shows (Heart preference but doesn't promise values).
It strikes me as completely bizzarre to describe the latter agreement as a "semi-psychic".
2. Further, I will agree that some partnerships don't do a particularly good job explaining what their 2
♠ response shows. I put them in precisely the same category as all those people who can't describe:
What a 1
♠ overcall of my strong club opening shows
What they're "could" be short 1
♣ opening does/does not show
When precisely they respond 1
♦ to a 1
♣ opening
How often they upgrade / downgrade a 1NT opening
Whether a 2
♥ rebid after a 1
♦ and a 2
♣ response promises extra shape
What their 2NT response to partner's 1
♣ opening shows
I think you get the picture... In case you don't: Perfect disclosure is a wonderful idea which, all too often, fails in practice. Fixating on this specific auction strikes me as rather bizzarre. As a practical example:
I've played against a fair number of pairs who play a multi 2
♦
I've played against a lot of pairs who overcalled 1
♠ over my strong club opening.
Want to hazard a guess when I get better disclosure?