The precincts reporting number only provides a very rough estimate of the progress of counting of total ballots for a couple of reasons. First, it only reports on ballots cast at polling places on Election Day. It does not take into account any Vote-by-Mail ballot totals. Second, it is simply a snapshot of how many precincts have had their Election Day ballots run through the ballot scanners. It does not take into account the number of ballots in a precinct. Some precincts have hundreds of ballots and other precincts have no ballots at all! So, there is not always a direct correlation between the number of precincts reporting and the number of ballots counted.
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The reason is that there are many precincts that have zero voters and in our software program precincts with zero voters aren’t reported until all other precincts have reported their results. So on Election Night it is possible that the percentage of precincts reporting can suddenly rise to 100 percent without a drastic change in the number in the vote count.
To give some perspective to this issue, there are 1,609 precincts in San Bernardino County. Of those, many precincts are located in remote areas of the County and have very few registered voters residing in them. In fact, 438 precincts have no registered voters in them at all.