[kq76]

I don't think the odds depend on what really happened. For example, say your league is only 9 years old and the event in question has never happened, but in the 10th year it does. Does that really mean it's going to happen at the same rate if the league ran for another 1000 years? No, not at all. If it's odd enough it might never happen again and so the % you calculated based on only 10 years would be wildly inaccurate over 1000 years.

A better way, I think, to calculate the odds would be to run OOTP 1000 seasons and see how often it happened in OOTP, but that'd be a lot of work just for curiousity's sake. I'd just take the win that something happened that you think you might never see again.