edit: I mixed up yearly statistics vs "lifetime likelihood". I'll leave what I wrote for posterity

If the US population is 328,000,000, and each of us has a "1:11,125 odds" of dying in a mass shooting, that would seem to indicate that there are 328m/11,125 = 29,483 "mass shooting deaths" in any given year (I'm happy to accept corrections on my math here, maybe I'm completely missing something). That's patently false, and quite a spurious definition of "mass shooting". My definition of "mass shooting" is an unprovoked attack for terroristic reasons. i.e. NOT a { jealous spouse/drug dealers/gang bangers }. I don't keep an active tally, but I would estimate the number on an "average" year to be about 50, double that during the year we had the vegas shooting. 50/year puts the odds at rougly 1:6,560,000, or about 40x less likely than getting killed by a lightning strike.