https://en.wikipedia.org/wiki/Allan_Lichtman
"Allan Jay Lichtman (born April 4, 1947) is an American political historian who teaches at American University in Washington, D.C. He is well known for predicting the election results for the president of the United States Presidential Election since 1984, including forecasting the 2016 U.S. Presidential Election remarkably early."
The 13 Keys to the White House
https://pollyvote.com/en/components/index-models/keys-to-the-white-house/
"When five or fewer keys are false, the incumbent party wins; when any six or more are false, the challenging party wins."
"Prospectively, the Keys to the White House has correctly forecast the popular vote winner of all seven presidential elections from 1984 to 2012, usually months or even years prior to Election Day."
1 Party Mandate - After the midterm elections, the incumbent party holds more seats in the U.S. House of Representatives than it did after the previous midterm elections.
2 Contest - There is no serious contest for the incumbent-party nomination.
3 Incumbency - The incumbent-party candidate is the sitting president.
4 Third party - There is no significant third party or independent campaign.
5 Short-term economy - The economy is not in recession during the election campaign.
6 Long-term economy - Real per-capita economic growth during the term equals or exceeds mean growth during the previous two terms.
7 Policy change - The incumbent administration effects major changes in national policy.
8 Social unrest - There is no sustained social unrest during the term.
9 Scandal - The incumbent administration is untainted by major scandal.
10 Foreign/military failure - The incumbent administration suffers no major failure in foreign or military affairs.
11 Foreign/military success - The incumbent administration achieves a major success in foreign or military affairs.
12 Incumbent charisma - The incumbent-party candidate is charismatic or a national hero.
13 Challenger charisma - The challenging-party candidate is not charismatic or a national hero.