[dahart]

You're right; there is indeed a large risk difference between football and base jumping. Though it has recently come to light (in the public consciousness) that football carries significant risk of concussion and CTE with prolonged exposure. As a parent, and having talked to many parents about this, football is not as widely accepted as being safe as it was ten years ago.

That said, this has no bearing on my point above. It doesn't matter whether society has deemed some activity safe or not. What I'm saying is that skill and preparedness is a secondary factor in how much risk you bear for any sport or activity. The primary risk factor is how much exposure you have to the activity, how long you choose to do it. This is as true of walking on the sidewalk as it is of playing Russian Roulette.