One of the critiques about how Fox News determined who would qualify for its wildly popular first Republican presidential debate was that it was something of a black box. Which polls would count? What would happen to the people that barely register at all? And the constant: Who's in, who's out?

CNN is clearly determined to avoid a similar critique. Its published criteria for inclusion articulates seven checkboxes each candidate must tic, and specifies precisely which polling firms will be included. In short, the process looks like this:

1. Any poll from qualified pollsters released between July 16 through Sept. 10 will be included in the average.
2. The candidates with the top 10 polling averages will be invited to the main debate ...
3. ... Assuming that they meet the other requirements: Having visited and having paid staff in two of the four early primary and caucus states.
4. Those of the 16 eligible candidates who don't make the top 10 but who have polled at 1 percent in at least three of the polls get to participate in the earlier debate.
5. In the event of a tie for the top 10, another set of polls will be used to break it.

We'll dive into that more in a second. But for now, here's how the stage(s) would look if the debate were today -- again, assuming that CNN puts the higher-polling candidates more toward the middle. (We skipped the third point in our consideration, we'll note.)


The first thing you'll notice is that there's Donald Trump, right next to Jeb Bush, same as before. And the second thing -- hey, wait. Wasn't there supposed to be a shake-up? And why's Fiorina still sitting at the "kiddie table?"

The answer lies in the first point above. CNN isn't tracking the state of play, as Fox did. Fox looked at the five most-recent polls, meaning that it reflected how things stood at the end of the time period. CNN is using far more polls, including 10 than have already been released. In other words, where Fox's system was meant to see where the speedboat of public opinion happened to be, CNN wants to know where the ocean liner of opinion has headed.

That's tough for Fiorina. There are already eight polls in the mix that show her at 2 percent or lower. She'll need to prolong the post-debate bump for the next month or so -- and hope for a lot of polls -- to slowly shift that average up. If there were only two polls in the mix, where she was at 1 percent in the first and 5 percent in the second, she'd be at 3 percent on average. If there are 10, where she's at 1 percent in the first nine and then gets the 5 percent just now? Her average is 1.4 percent.

Despite CNN's attention to detail, there are still some questions. Rick Perry isn't paying his staff, for example; does he meet the standard in no. 3, above? And so on.

As always, we'll keep updating this as the big day approaches. But given CNN's use of far more polls, this one is a lot less likely to change dramatically over time.