I think one way of identifying above average asset managers is by finding the ones that specifically use CFS - Computer science, Finance and Statistics because I have found that these managers' models are sufficiently robust and cross-validated at a sophisticated level to improve the odds for success. I can think of three of such managers - but I will only mention one. :-)

PCPpresentation.com.

Cross-validation, stress testing, out-of-sample testing are all important questions to ask managers in order to rule out those managers that simply run over-fitted, over-optimized portfolios with lookback bias and whose models are based on past assumptions - which may or may not hold true in the future. A dangerous combination imho.

https://www.hvst.com/posts/63417-how-everyone-can-prepare-for-a-more-un…