It may be the case that a race that has a fast average speed will suit a certain type of rider. If the flat bits are raced consistently hard that is probably going to suit the bigger riders more than the smaller ridersCaruut said:Not useful to determine anything about the winner. You can make some conclusions about the bunch (or more accurately the roleurs on the top teams) and the route, however.
Mainly though I think the thing that race speeds reflect more than anything is the weather. I'll bet the slowest Tours correspond to the wettest Julys