He made his conclusions by running the numbers for each game this year through a statisticalregression and confirmed the results by testing games from previous years.
These two correlations do not by themselves prove that chronic stress damages the memory, but Dr Evans and Dr Schamberg then applied a statistical technique called hierarchical regression to the results.
For most major league seasons when running a statistical technique called simple linear regression, the number of wins is statistically correlated with team payroll.