(Jonathan Frink voice intensifies) For a single assigning of range, you have a start point and end point which allows for 784 * 783 / 2 combinations which is ~300,000 but since some people might opt for multiple ranges (ie: S02E07 - S09E17 & S21E13 - S31E11), that expands the result space. At it's limit, people could simply list their qualifying and non-qualifying episodes in a binary fashion which results in 2^784 combinations which is approximately 10^(784/10*3) (because 2^10~10^3) or 10^235. This is far more than the global population so pigeonhole principle wouldn't apply.

How do you figure?

Assuming ranges are A-B, where A <= B (you could like one season) and A, B are in [1, 28] then there should be just 406 ranges (28 that start at season 1, 27 at 2, etc...).