Controversial! But interesting idea for a project. The mountain running data would have to be taken from races where navigation is not a significant factor.
Yeah i was guessing someone would say that alright. Obviously the last thing i want to do is stir up controversey. Just looking at this purely from a statistical point of view :)
And yeah, it would have to be a totally navigation-free race.
World/European Mountain Running races would not have any navigation, but be careful which years you use as some are up only with other years up and down.