The ACBL does not like psychic bidding, let's face it. If the Rules say that you can, that only gets you so far. When you start actually whipping one out here and there, your partner inevitably will end up at some point in some interrogation, thinking that he needs an attorney. Why? Usually you either made a really good psychic, or perhaps partner was not a complete dolt and noticed that 50 points in the deck, two sweating and confused opponents, and favorable colors suggested a "forcing pass" solution to a bidding problem.
At one point, years ago, I grew so frustrated with the nonsense that I decided to develop a new type of bid entirely, one that I called a "Steppingstone Bid." I wonder, still, how the GCC and Rules account for this beast.
I mean, we all know that there are types of bids. A "normal" bid shows what you have and designates (in theory) a possible strain and proposed level. Natural. Then, you have asking bids, relays, puppets, marionettes, and other varieties of bids. But, what about a "Steppingstone Bid?"
A "steppingstone bid" is defined (by me) as a call that is not forcing upon partner but that "forces" the opponents to take action to unwind your possible meanings. That's not even right as a definition.
The situation is one where you try to maximize "useful space" and you stack meanings efficiently by taking advantage of a scoring-based situational "force." That still doesn't explain it well.
OK, an example. Partner opens Two Hearts, weak. You are playing that any call at the three-level is forcing, 2NT is Ogust., and 3H is a raise. But, Two Spades is a non-forcing response. So far, fabulous. But, you realize that you cannot show a weak hand with one or both minors.
So, you decide that 2S instead shows one or both minors, weak. If partner prefers diamonds, he bids 2NT; if clubs, 3C. You then place the contract accordingly. That's better, in that you handle more hands, but then you cannot get out in spades.
Suppose you decide that, white on red, you will play that Two Spades shows either spades OR one-or-both-minors. Suppose, further, that you play 2S as non-forcing. How, then, will partner know what you have? Easy! The auction becomes, in a sense, forcing. Why? The opponents cannot defend 2S if you have one or both minors because they make +620 or better in Four Spades and get at most +400 against Two Spades undoubled. Thus, Two Spades is, in a sense, "forcing." Just, you partner is not the one who is forced.
Now, how can that type of call be treated as a psychic when the advantage gained is obvious? You stack bidding space up, which is constructive. This may be an unusual type of convention, and it may resemble a psychic, but alerted and explained, it is not.
So, take this a step further. Partner opens Two Hearts in third seat. After a double, you could play Suit/Lead. Suppose, instead, that you want to play a method where Responder can escape to a long suit OR suggest a lead, but you want to also be able to play Two Spades, or to bid 2NT as both minors. If you start working this up, Steppingstones works (at least white on red). Bid a suit that you either want as the lead (shortness perhaps) or that you want to declare. The opponents are situationally forced to unwind this for you, meaning that you stack meanings and thereby are "constructive." The fact that this ends up looking a lot like a classic psychic is irrelevant. Your purpose is honorable, efficiency results, and alerts clear up the ambiguity (somewhat) for the opponents.
So, then, is this a "controlled psychic?" That's the rub. By my thinking, a "controlled psychic" is a term that makes no sense. If one can ask whether you have X or Y, and if you can have X or Y, then having X (the "psychic" meaning) is not a psychic because you by definition can have that holding. So, I have no idea what a "psychic control" is. However, if this means a way to back-door a meaning that is not otherwise allowed, OK. Call it that. Whatever -- the point is that a "Steppingstone" should be allowed if alerted and explained when all possible weak meanings are allowed as conventional responses, of course. Then, it is not a psychic and hence there are no psychic controls. For that matter, by definition, PARTNER is not using any "control" anyway; the opponents are the ones who are "forced." I cannot imagine that the GCC prohibits calls that force the opponents to do something intelligent if they want a good score (or try).
I bet there are other uses for Steppingstones, like perhaps even a Steppingstone Pass? I mean, in theory we all do THAT call. LHO opens 1NT. RHO transfers. You pass, planning on making a different call when the auction comes back to you, because you know that the auction MUST come back to you, as LHO cannot pass. He is forced. So, you stack meanings in this manner. The question is whether there are more situations where you can "Steppingstone" auctions.