“That’s the best case scenario?” Alexandria asked.

It’s interesting that he seems to think a 51.4% population reduction is better than a 33% reduction. Maybe he’s accounting for overpopulation?

(Someone get Thanos in here.)

The man shrugged.  “It’s unlikely it will occur.  The bare minimum of people would have to die, there couldn’t be any bodies, and there wouldn’t be anything left unattended that could cause uncontrolled fires or nuclear incidents.

Oh wait, I see what he means now. That best case scenario is what would happen after a third of the population dies to the apocalypse.

If I were to ballpark a number, talking about events that could kill one-third to nearly all of the world’s population, I’d say roughly seventy-two percent of the earth’s population are likely to die.  That leaves one billion, nine hundred and fifty million alive.

Damn.

Also, while I don’t think fast math is the full extent of his power, it does seem to be a part of it.

More than half of those individuals would die over the following twenty years, and more than half of those who remain would die in the ten years following that.  Keeping in mind these are estimates, of course.”

So then after thirty years we’re down to a quarter of 28%, i.e. 7%.

“Of course,” The Doctor said, “Precogs are unreliable.  I’m surmising this girl doesn’t know exactly how this occurs?”

I think I’ve got a better idea due to the kind of future vision I try to avoid.