Are you a good stock picker?

A few days ago, I posed the question to this group, asking about benchmarking. I think we collectively pretty much all compare our performance against the S&P 500...which is a good benchmark as it's an easy alternative to portfolio construction. But I think ***there's a better way to judge investing skill***. And that is to compare ourselves to chance. More to the point - how did I perform relative to how I would have performed had I simply chosen a portfolio at random (think about you competing against a *bunch of monkey's at bloomberg terminals*). That starts to answer the question of '***Am I able to pick more good stocks than bad stocks?***'. This is a much better starting point in my opinion. The S&P is also a fine yard-stick, but it's also a moving target. In the last few years, the S&P has been in the top 30% of all potential portfolios. But this hasn't always been the case in the past, and I don't think it'll necessarily always be the case in the future. I think this quote sums it up perfectly: >I often find investment ideas that I expect to return somewhere in the 12-15% range over a 5-year period, and I’ll catch myself wondering if that will even be enough against the backdrop of 20% annualized S&P 500 and AI returns. In the article, I also propose a scoring system - ***Z-Score*** \- to statistically measure skill. I also propose the concept of the ***Mendoza Line*** \- or the performance level at which you can decidedly be called a 'replacement level player' in portfolio management. This level is being able to construct portfolios above the 30th percentile of all possible portfolios (rolling returns for this are plotted in the post). If you are consistently below this threshold, you're actively destroying capital, and should consider changing strategies. Anyways, it was just an interesting thought experiment, and was fun crunching the data. Curious if you guys have any thoughts or pushback. ***Would you consider changing your benchmark to the median portfolio?***