The giant Republican presidential field has created tough choices for the hosts and organizers of presidential debates. You can't let ALL 17 candidates on stage! They say.
There's something to that — a super-crowded stage would result in either a very long debate or very perfunctory answers, or very few questions.
So drawing a line somewhere makes sense. After all, it's not true that there are 17 candidates. In fact, over 100 people have filed to run for president, almost all of whom you've never heard of (though one may well be your next-door neighbor).
I would prefer taking the top 17 or so, and dividing them randomly into two different debates. Then maybe in a second go-around, mix them up again to maximize the number of combinations.