In an analysis of the performance of Major League Baseball players, Schaal and Smith (2000) found that the batting scores of the top 10 players in the 1997 baseball season dropped on average in 1998. What is the best interpretation of this finding?

a. Players who did well in 1997 reduced their effort the following year, realizing that they didn’t need to work as hard to get an above-average result.

b. Players performing above average in 1997 were older and more worn out by 1998.

c. Regression toward the mean.

d. Possibly (a) and (b), but (c) is likely and cannot be ruled out.