A simple rule of thumb is that for samples with N < 100 be very skeptical for the results as those can be archived simply by randomness on top of small systemat

A simple rule of thumb is that for samples with N < 100 be very skeptical for the results as those can be archived simply by randomness on top of small systematic errors. Proper statistics helps to rule out randomness, but not systematic errors. Which pretty much rules out most of the sport studies.