Challenging the 85% rule

[Scott R. Brown]

Since every fight begins with feet touching the ground, 100% of fights start on the ground.

Since every fight ends with feet or body touching the ground, 100% of fights end on the ground.

The ground is very popular it seems!

[Lucas]

You never met my combat yoga master Dhalsim!

[Syn7]

If two unskilled people clash, yes it stands a significant chance of going down. When people don't know what to do they just swing and hold on. If they both hold on, they end in a grapple and usually, but not always, this ends up on the ground. Especially when you take education into consideration. Almost everyone does some wrestling in school and with their buddies when they are kids. Significantly less people actually practice fighting.
It's also cultural. most cultures teach some form of grappling to kids in school. Where I live wrestling is part of the legal curriculum. It must be taught, no excuses.
When it comes to trained fighters, it depends entirely on the raining. If two BJJ cats fight on the street, I would say yes it stands a huge chance of going down. If two boxers go at it, it will probably stay standing. Till the end anyways.

There is no one formula to define all fighting. It really depends on the fighters.

MA's are not delusional because they think fights stay standing (which is not always true), they are delusional because so many think that you can trade back and forth like on TV in a real fight, catch punches and do small point(not joint) manipulation in a frenzied combat situation with strikes from a distance.