SATTSO, so we are talking about the same thing, what is the TSA's definition of "risk", as that term is used in "risk based screening"?

I'm asking because risk typically is the likelihood and impact of an adverse event. Using that definition, I fail to see how the CBP programs directly allow an individual's risk to be measured. To the contrary, the "risk" element in play seems to be entirely qualitative and judgmental.

That doesn't mean the programs are bad, it just means they essentially come down to the TSA saying "we believe these people are good enough, and those others are not".