Tennis requires the ability to calculate infinite variables while not thinking at all. The physics are gnarly but preconscious. Reflexes and muscles, eye sensors and veins, execute the work, and adjustments are made as a machine recalibrates according to conditions. A winning strategy requires immense brainpower, but its intelligence is narrow; it admits no ambivalence or second thoughts. What is called the ability to focus, the mind of a champion, is more like having no mind at all.