Question - why do post time favorites lose?

[Bill Lyster]

We all know that post time favorites win between 30 and 35% of all races (or you pick the %-age.) So I was wondering if one was to try to quantify what factors were most prominent for those favorites that lost, what would they be.

If you are inclined to add to some input to this discussion, please comment on why you think the factor being discussed points to a non-winning performance. If you have data to support your idea, please include it.

I am looking to do some research, but I am trying to avoid doing it multiple times. So many times I've researched stuff and then, when I thought I was done, I wondered what would happen if I added _____. It almost takes as much time to add something to a project as it does to record the info the first time, so my asking is a start at trying to limit the laborious task at hand.

Looking forward to your input and thanks in advance.