There has been a significant debate in psychology over the past 20 years about skilled performance. The debate comes down to the difference between talents and skills, where talents involve traits of an individual that affect performance, while skills involve things that people learn.
For a long time, the talent explanation was dominant. Most people just assumed that the best performers in art, music, sports, and academics were the ones who had the most natural talent. Skilled performers have to practice, of course, but the talent was assumed to be more important than practice.
The latest paper to make this case was written by Brooke Macnamara, David Moreau, and David Hambrick and appeared in the May 2016 issue of Perspectives on Psychological Science. This paper focused on the role of practice in sports. These researchers performed a meta-analysis of studies.
Overall, amount of deliberate practice accounted for 18% of the difference in performance of athletes in the sample. That is, 82% of the difference in performance among athletes does not reflect practice. This relationship between practice and performance was true for athletes in both team and individual sports. It was true for sports that are externally paced (like hockey or volleyball) or internally paced (like bowling or darts). It was true for ball sports and non-ball sports.
Practice does help to distinguish between sub-elite and elite athletes. Studies that looked at both types of athletes in the same study suggest that practice accounts for about 29% of the difference in performance among athletes. That is, amount of practice may help to distinguish a bit between elite athletes and others, but still most of the difference in performance is due to other factors.
Source material from Psychology Today