Georgia and Louisiana are the only states that provide for general election run-offs if no one gets 50% in the general election. Because the Georgia Libertarian Party is ballot-qualified for all statewide offices, sometimes the presence of the Libertarian means that no one gets 50% for U.S. Senate. In 1992, 2008, and 2020, Georgia thus had to hold a January run-off for U.S. Senate. Since then, the date of Georgia general election run-offs has been changed to December of the election year, so any 2022 runoff will be December 6.
The 538.com website shows polling for the 2022 Georgia U.S. Senate race for the past several months. Although the lead has shifted over the months, the poll consistently shows that the race is so close that no one will get 50% in November.
In the 2020 election, the majority party in the U.S. Senate was not known until the Georgia January 5, 2021 runoffs.