Whereas this approach doesn’t seem as intuitive as simply looking at positive and negative returns, it is a bit easier to work with. No matter what the length of the period, the market return is just about as likely to be above average as below average; this more closely resembles a fair coin for each experiment. This is not true for the positive/ negative distinction, because the market tends to rise, especially over longer periods. In any case, the resulting conclusions are not sensitive to which technique is used.
