Professor Allan Lichtman knows who is going to win the election.

Lichtman, who teaches history at American University, doesn’t use polls or trends to determine the winner. He uses a unique methodology that has given him the correct prediction in every presidential election since 1984. And this year, that methodology – Lichtman’s “Keys to the White House” – is sending him a signal that flies in the face of the media’s narrative: Donald Trump will be the next president of the United States.

In an interview with the Washington Post, Lichtman explained the system:

The keys are 13 true/false questions, where an answer of “true” always favors the reelection of the party holding the White House, in this case the Democrats. And the keys are phrased to reflect the basic theory that elections are primarily judgments on the performance of the party holding the White House. And if six or more of the 13 keys are false — that is, they go against the party in power — they lose. If fewer than six are false, the party in power gets four more years.

According to Lichtman, President Obama’s high approval ratings don’t mean much in his system because the president isn’t running. His popularity does not necessarily translate to his would-be successor, particularly since she does not have a fraction of his charisma. He says that to keep the White House, the Democrats need to keep the number of “false” keys under six. Right now, they’re teetering at five:

Key 1 is the party mandate — how well they did in the midterms. They got crushed.

Key number 3 is, the sitting president is not running.

Key number 7, no major policy change in Obama’s second term like the Affordable Care Act.

Key number 11, no major smashing foreign policy success.

And Key number 12 [charisma], Hillary Clinton is not a Franklin Roosevelt.

Lichtman said it all came down to the final key, which is the strength of a third-party candidate. In 2016, that key has a name: Gary Johnson. If Johnson can get at least five percent of the vote, Donald Trump will win on November 9th.

Right now, Johnson is polling between 12% and 14%.

Lichtman thinks Trump will win, even though he acknowledges that the Republican nominee’s unpredictability could make his system obsolete.

“Donald Trump has made this the most difficult election to assess since 1984,” he told the Post. “We have never before seen a candidate like Donald Trump, and Donald Trump may well break patterns of history that have held since 1860.”

Let’s hope, in this case, that the historical norms hold true.