Attention, Gary Johnson and Jill Stein: The Commission on Presidential Debates has revealed exactly how it will determine who gets to be on stage this fall.

In a normal election season, this announcement wouldn't matter much.

But this year Johnson, the Libertarian Party nominee, and Jill Stein, the Green Party contender, are both hoping to make the cut.

Donald Trump and Hillary Clinton are the only two definite participants, since they are polling well above the commission's 15% threshold for invitations.

Johnson and Stein are below the threshold and are trying to change that between now and mid-September. That's when the commission's "selection criteria" will be applied.

On Monday, the commission announced the five polls that will be averaged together to determine who is receiving 15% support nationwide.

The polls are ABC-Washington Post; CBS-New York Times; CNN-Opinion Research Corporation; Fox News; and NBC-Wall Street Journal.

The polls were chosen with "the professional advice" of Frank Newport, editor in chief of Gallup, the commission said.

The commission announced the 15% threshold in October 2015. But now it is explaining the process in more detail. The criteria "will be applied in mid-September," the commission said, not naming an exact date.

The first debate is scheduled for September 26.

"If a candidate is invited to the first presidential debate, that person's vice presidential running mate will be invited to the vice presidential debate," the commission said. "The criteria will be reapplied between the first and second presidential debates and the second and third presidential debates."

In other words, if Johnson or Stein aren't polling above 15% by mid-September but start to edge up after the first debate, they still have a chance to make it onto the stage.

CNN added up the results of the most recent ABC, CBS, CNN, Fox, and NBC polls to assess where the four candidates stand today with the commission's criteria in mind.

The results cover a period from July 29 to August 4. Clinton has 44% support, Trump has 36%, Johnson has 10%, and Stein has 5%.

The most recent CBS and Fox polls did not include Stein. If they continue to exclude her, "the average will be based on the polls that include a given candidate," a commission official said Monday.

But that may be irrelevant. A Fox News spokeswoman said Monday afternoon that Stein would be included in its polling.

CNN is holding a Green Party town hall with Stein on Wednesday night. The network has previously televised two Libertarian Party town halls with Johnson.

Jennifer Agiesta contributed reporting.