~ predictor for chess skills﹕ hours spent analyzing master's games

You analyze a position in depth, predicting the next move, and if you get it wrong, you go back and figure out what you missed. Research has shown that the amount of time spent in this sort of analysis—not the amount of time spent playing chess with others—is the single most important predictor of a chess player’s ability

❐ Peak - Secrets from the New Science of Expertise