Part of the answer, which seems to apply in every domain, is that they had more knowledge about their field. In chess, researchers have found (using a method I’ll describe a little later) that master-level players possess more chess knowledge than good club-level players by a huge margin, a factor of ten to one hundred. Just as important, top performers in a wide range of fields have better organized and consolidated their knowledge, enabling them to approach problems in fundamentally different and more useful ways.
