The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.NEW YORK ( Magic Diligence) -- The safest and most reliable path to stock market success is to invest in CRAP stocks. The strategy we follow, Joel Greenblatt's Magic Formula® Investing, is a great mechanical, qualitative screen for digging up candidates. But to find the CRAPpiest of stocks, we need to get our hands dirty and dig our noses into the financial statements, conference calls, SEC filings and industry research. Only then can our portfolios come out smelling like roses. What in the heck am I talking about? Four points of research: 1. Conservatively managed The best companies are managed conservatively, and are always focused on earning high returns on capital instead of overpaying simply to grow or build an empire. By maintaining reasonable levels of debt and always having a healthy cash balance for the inevitable bumps in the road, these companies are built to last through thick and thin.