Macnamara, Moreau & Hambrick 2016, Deliberate practice and sport performance, a meta-analysis

Meta-analysis of deliberate practice and sport performance. Accumulated practice explained about 18% of the variance in performance overall, but only around 1% among elite-level performers, and higher-skill athletes did not start their sport earlier in childhood than lower-skill athletes. A direct corrective to the idea that structured training hours alone determine success. Strong (meta-analysis).