(NewsNation) — As of Monday, Decision Desk HQ’s model predicts that Republicans have a 57.2% chance of controlling the Senate, with the GOP projected to control 51 seats compared to the Democrats’ 49.

So what does that actually mean?

If the 2022 midterms were held 100 times, Republicans would be expected to capture a majority 57 times, while Democrats would be expected to maintain their majority 43 times.  

In other words, it’s going to be close.

How does Decision Desk HQ make their calls?

Before analysts can call a race, they need to have a pretty good idea how many votes have been counted and how many votes still remain. Those turnout estimates are based on historic trends. Using population data and numbers from prior elections, forecasters predict how many votes are expected from each county in a given race.

As county-by-county numbers start to come in during Election Day, the models adjust and can calculate, with some level of certainty, the number of ballots that remain outstanding throughout the evening.

A group of analysts will be stationed at NewsNation headquarters, receiving information from about 1,000 additional employees working to get election results in real time. The data comes straight from the source, with teams contacting election offices throughout the country.

“The decisions are only as good as the data that we have,” said Drew McCoy, president of Decision Desk HQ.

As results come in and analysts learn the spread between two candidates, they then look to see if there are enough votes remaining for the candidate in second place to make up the difference.

“It’s a lot of research, it’s a lot of people in there that have tremendously detailed knowledge of the states and the counties and even down to the townships that they are assigned to cover,” McCoy said.

Of the more than 20,000 races that Decision Desk HQ has called, only two have missed the mark. McCoy said. He added that accuracy takes strategy, enduranc, and patience. 

Scott Tranter, head of data science, said the important focus is on accuracy, not speed. If races are close in key battleground states of Pennsylvania, Georgia, Nevada and Arizona, it could be weeks before a winner is called.

“We want to make sure we get it right the first time,” Tranter said.