The heritage is interviews, and interviews are the least transferable form of knowledge.

What testimony is

A retrospective account, by an interested party, with no control group.

The form has known properties. It is retrospective, so the account is reconstructed rather than recorded. It is given by someone with an obvious stake in the coherence of their own story. It describes what the speaker believes mattered, which is not the same as what did. And it comes with no comparison case — no equivalent account from someone who did the same things and failed. None of this makes testimony worthless. It makes it evidence of a particular kind, requiring a particular handling, and treating it as a specification is a category error that produces confident nonsense.

The test applied

Keep what could be turned into a reading. Set aside what could only be admired.

The filter used is narrow and mechanical: could this claim be expressed as something measurable on a trade record. Cut losses quickly survives, because it becomes a stop discipline with a level and a logged adherence flag. Judge results over a large sample survives, because it becomes a minimum sample before a conclusion is legal. Have the courage of your convictions does not survive, not because it is wrong but because nothing about it can be read off a journal, which means it can never be checked and never be improved.

The third column is the dangerous one

A practitioner's theory of their own success is still a theory.

The interpretive material is the most quotable and the least reliable. When a successful trader explains why their approach worked, they are doing what anyone does with their own history — constructing an account that fits. That account may be right. It is also unfalsifiable from the inside, and it is the part of the tradition most often adopted wholesale, because it is the part that sounds like wisdom. The inheritance deliberately takes the operational claims and leaves the explanations, on the grounds that a mechanism can be tested and a philosophy cannot.

What this leaves behind

Some of what was discarded was probably the good part.

Honesty requires saying that the filter is crude. It selects for what happens to be measurable on a trade record, which is not the same as selecting for what matters — and it is entirely possible that the untransferable material, the judgment and pattern sense built over decades, accounts for more of those practitioners' results than everything that survived the cut. The system does not claim otherwise. It claims that the measurable subset is the part that can be operated deliberately by someone else, and that a smaller inheritance held accountably beats a larger one held on faith.

• The filter selects for measurability, not for importance.
• The discarded material may well be where most of the original edge lived.
• What survives is what a second person can run without becoming the first person.

Why the provenance is written down

A rule with a stated origin can be re-argued. One without cannot.

Every principle carried across from the tradition is attached to where it came from, which sounds like scholarly courtesy and is closer to a maintenance requirement. A rule whose origin is recorded can be revisited when the evidence changes: it came from here, it was adopted for this reason, and the reason can be examined. A rule whose origin has been forgotten acquires a different status entirely — it becomes something the system has always done, and its only remaining defence is its own longevity.

The key idea

Inheriting from practitioners means deciding what in their account was a mechanism.

There is no way to take a tradition of testimony seriously without also taking a position on which parts of it are operational. Refusing to choose means adopting all of it, including the biography and the self-theory, which is how a lineage becomes an aesthetic. The choice made here is deliberately conservative and it gives up real material — and it means every inherited principle can be pointed at a trade record and asked whether it is still true.