As an investor , my test on allocation for an equity advisor is performance after fees for at least one full market cycle ( now by coincidence sbout 10 years )
and better still two full cycles .

Annualized return,sortino alpha, beta , max drawdown , up/down capture metrics .Very few advisors do very well risk adjusted long term.
Frankly MPT has its uses if not too rigidly applied as does BF ..and risk reduction based on extreme valuations .

all these theories are fine , but long term full cycle net risk adjusted returns as above are what finally cut the mustard

Have read many authors on and off this site that sound good but cannot show metrics as good as a handful of mutual funds with same manager we screened on these metrics metrics defined above and outperform handily .. and persist at least 5-10 years .
Happy to hear from any RIAs /CFAs who agree and have such track records .
Rare birds indeed .
thanks , marvin