First off, I would like to point out that you are in the wrong thread for this sort of question. This thread has been dead for 2 years and is referencing a simple online game.
Now, that being said, it really depends on a lot of things. I mean, technically, it's what bike companies sell you. That being said, people race DH on hardtails with 100mm of travel all the time, albeit less common than racing DH bikes haha. Also, if you live in Ontario anyone who tells you that you need more than 4 inches of travel is lying, unless they're referring to the bedroom. I would recommend taking this question to a thread involving said topic or creating a new thread.