Visual uncertainty influences the extent of an especial skill

An especial skill in basketball emerges through highly repetitive practice at the 15 ft freethrow line. The extent of the role vision plays in the emergence of an especial skill isunknown. We examined the especial skills of ten skilled basketball players in normaland blurred vision conditions where participants wore corrective lenses. As such, weselectively manipulated visual information without affecting the participants’ explicitknowledge that they were shooting free throws. We found that shot efficiency was significantlylower in blurred vision conditions as expected, and that the concave shape of shotproficiency function in normal vision conditions became approximately linear in blurredvision conditions. By applying a recently proposed generalization model of especial skills,we suggest that the linearity of shot proficiency function reflects the participants’ lesserdependence on especial skill in blurred vision conditions. The findings further characterizethe role of visual context in the emergence of an especial skill.