First - Players should report their own psyches, it is not the oponnents' job to do so.

Second - It is unclear from your post what the opening bid was. If it is was 1C then this is an illegal psyche IMO. The Manual, page D80, states that:

"It is prohibited to "psyche" any conventional opening call that has as one of its options a hand that

(a) may contain 13 or more HCP, and 

(b)is unlimited, and

(c) does not show either a specific suit or a balanced hand."

I believe a Precision Style 1C opener meets this criteria. If I am reading this wrong then could someone please clarify.

Ed

Firstly they opened 1 Diamond.

Edward, you write, Players should report their own psyches .

Why would anyone report that they were fielding third hand Precision 1 Diamond bids, probably on a regular basis?

My question has even more validity if indeed it is a psyche, as who is going to report themselves for a 3rd time? And worse, if they have already done it twice, their partner will know that the next time is genuine. 

1D here is not a psyche IMO. It is not an unreasonable "light" opener in 3rd seat. However, if it is partnership agreement to always open with 8 HCPs on third hand then it should be part of the system and alerted.

As to the other point - there are such things as ethics. Bridge is a very easy game to cheat at. I expect people to play and act ethically. If they don't they will eventually get caught.

In an earlier forum Fraser Rew posted this guideline for definition of a psyche

"if you can change ONE card to any other card of your choice and produce a sound bid then it is not a psyche"

I don't know if this has any official status or not, but if it doesn't I think it should, as it is very good in my opinion (and consistent with the requirement a psyche must be "gross")

In this example turn a small card into the Ace of diamonds and you get a 12 point hand with 5 diamonds. Anyone who thinks that is not a sound opening needs to be locked away somewhere where they can't harm themselves too much!

Also there is no rule limiting the number of psyches permitted in a session. The only rule is "no persistent psyching".
As a guideline it is stated two psyches in a session is evidence of persistent psyching.
"Evidence" is different from "proof".

No jury would find a person guilty of a drive-by shooting if the only evidence was a smoking gun found in the back seat of his car

In my view a player who habitually makes completely random psyches once every session is psyching persistently.
But one who makes two semi-constructive psyches in one session is not

Nick Whitten

PS just in case anyone wants to know what I mean by "semi-constructive psyche" I offer this as an example

Many years ago on a bidding forum the panel were asked what they would respond to 1D with (something like)
S: xxx   H: xx   D: AKQxxx   C: Ax

The majority chose 2C with comments like "if you invent a suit choose a lower ranking one and one in which you have an honour"
This is technically a psyche but it has a purpose other than confusing the opponents
And it could propel the side into a 6D contract which is only beaten on a club lead which the defence won't find now because of the 2C bid.