A University of Minnesota team went back through 85 years of hiring research and re-ranked everything employers screen candidates on. Years of experience came out at 0.07, on a scale where 1 is a perfect predictor and 0 is a coin toss. The old estimate, trusted since 1998, was 0.18. The new top predictor was structured interviews at 0.42, where every candidate faces the same questions scored the same way. Job knowledge tests came in at 0.40 and work sample tests at 0.33, which put all three in the top four. They are versions of one move. Hand the candidate the work and watch. Practice hours behave the same way. A 2014 paper in Psychological Science pooled decades of earlier studies to see how much of the gap between strong and weak performers came down to hours of practice. The answer changed a lot by field. Competitive games landed at 26 percent, music at 21, sports at 18, formal education at 4. For professions, practice explained under 1 percent of the difference. Three days of focused work comes to about 20 hours, which is the number Josh Kaufman landed on after teaching himself six skills from scratch for his book The First 20 Hours. Twenty hours takes someone from knowing nothing to visibly decent at the thing. Going past decent takes far longer. Cigar rollers in a Cuban factory, studied for a 1959 paper in the journal Ergonomics, kept getting faster for about two years and three million cigars before the curve flattened. Hiring practice has moved slower than the evidence. In 2024 Harvard Business School and the Burning Glass Institute checked what happened after companies publicly dropped degree requirements. Across more than 11,000 postings between 2014 and 2023, hires without a bachelor's degree rose 3.5 percentage points, but only 3.6 percent of roles ever dropped the requirement. Across the whole economy that came to about 97,000 workers out of 77 million yearly hires. Fewer than one in 700. On Indeed, 19.3 percent of postings now set a bachelor's degree as the lowest qualification they will accept. That share has been climbing again since early 2024. Employers surveyed by the World Economic Forum expect 39 percent of the skills their staff use today to be changed or outdated by 2030. The credential they screen for has a shorter shelf life than the person it screens out.