The Inquirer’s election results use data from the Associated Press.

The way we are reporting results looks a little bit different this year. In the past, the percent of the vote that has been counted was based on the number of election precincts that have reported results.

But this year, that number is based on the AP’s estimate of the total number of expected votes. The reason for the change is the unprecedented number of mail ballots in many states, including Pennsylvania, because of the coronavirus pandemic.

We may not know who won the presidency Tuesday night, and the “lead” may swing from one candidate to the other — more than once. That’s not fraud, that’s not the election being stolen, it’s just the votes being counted over time.

The AP estimates the expected vote by looking at:

  • turnout in recent elections

  • the number of mail ballots

  • how many votes were cast before Election Day

  • the returns from in-person voting.

And the number may change as elections officials report additional results and more information is available about how many voters have cast a ballot.

» READ MORE: What we will and won't know on Election Day

For the percentage of total votes cast, the AP calculates that based on the estimated expected vote and the number of votes that have been counted.

Since the percentage of total votes cast is based in part on the AP’s research, it may not match figures posted online by state and county elections officials.

When the AP declares a winner — which is what we use in our results reporting — it’s not based on a projection or a prediction. The AP calls a race only when it determines that the trailing candidate will not catch the leader.