The contributions Of motor skill and cognition (decision making and kn
owledge) to sport performance change across age, expertise, and sports
. Knowing how to execute a skill is a prerequisite for efficient and e
ffective execution. As skill execution improves, the cognitive aspects
of motor execution become automated. For low-strategy sports (e.g., s
wimming) variables such as physical size and ability combine with moto
r skill to determine expertise. In high-strategy sports (e.g., basketb
all) cognition remains an important variable in game performance. The
performer must know what to do and then be able to execute the plan. K
nowledge and decision making should not limit the development of exper
tise. Specific strategies for coaches and teachers may facilitate the
development of expertise in children and adolescents.