The ATP Tour has temporarily changed its rankings system because of the coronavirus pandemic, hoping to reward players who perform well when the 2020 season resumes without punishing those who can't or choose not to play.

A player will be able to count his best 18 results over the 22-month period that covers March 2019 to December 2020. The traditional window covers only 52 weeks.

The tour's rankings have been frozen since March 16, just days after the season was suspended. Play is set to resume in August ahead of the U.S. Open.

The tour said Monday it believes the revised system will allow for further changes in the calendar if necessary.

Players will not be able to count the same event twice if it was held in both 2019 and 2020. Points added through tournaments in 2020 will remain on a player’s ranking for 52 weeks or until the event is played in 2021, whichever comes first.