The thing is, to a statistician the word "average" can mean many, many different things. Fico is a system set up by statisticians.
For us non-statisticians, "average" will usually either mean the mid-point number where half of all people will be above and half below, or it is the mean (the sum of everyone's score divided by the number of people).
I would think that it obviously can't be the mean because the worst credit scores (say 300-600) are so much lower numerically than the best (say 800-850). In other words, I think that the low numbers would drag the mean well below 720.
I also don't think it can simply be the mid-point because as economic times get relatively worse or better the mid-point should be moving all over the place.
Now what the "average" MIGHT be is a re-centered mid-point. In other words, if they really want 720 to BE the mid-point they might occasionally figure out where the actual half-way point is and them MAKE that 720. If that is the case, it would then be possible for a person's score number to change without any of their credit record changing (even account ages) if the score is checked both right before and right after re-centering. Re-centering probably would move most peoples' scores TOO much as long as there isn't a complete economic collapse in between.
All of this is just idle speculation of course; the fact is the only ones who could say for certain would be Fair Isaac.
