The expected value should stay constant.

EV is calculated based on the Jones Probability.

JP is calculated based on total hits and total windows for the analysis time span.

None of those parameters change. Remember, in this case the total hits is the total hits on the real database for the consecutive time windows, not the total hits for the set of predictions.

The variance also does not change.

The Jones Score for each prediction can only be one of two values, depending on hit or miss.

The sum of the Jones Score is the only parameter that changes, based on the number of hits in each set of random predictions.

Brian