A Variance Explanation Paradox: When a Little is a Lot

Concerning a single major league at bat, the percentage of variance in batting performance attributable to skill differentials among major league baseball players can be calculated statistically. The statistically appropriate calculation is seriously discrepant with intuitions about the influence of skill in batting performance. This paradoxical discrepancy is discussed in terms of habits of thought about the concept of variance explanation. It is argued that percent variance explanation is a misleading index of the influence of systematic factors in cases where there are processes by which individually tiny influences cumulate to produce meaningful outcomes.