The ATP announced a revised system for calculating the men's tennis world rankings when the coronavirus disrupted season resumes in August.
Rather than the current system based on a player's "best 18" results over a 52-week period, the temporary revisions will see the rankings cover a 22-month period from March 2019-December 2020.
The tour said in a statement that the system is designed to provide fairness to players across all levels of the game in parallel with the condensed number of points available after multiple tournament cancellations, the tour said in a statement.
In addition, it should provide stability for players who cannot or prefer not to compete in 2020 because of health and safety concerns.
The ATP believes the system can adapt to further changes in the calendar if necessary.
The world rankings have been frozen since March 16, just days after the ATP Tour suspended play because of the Covid-19 pandemic.
Britain's Andy Murray had suggested last month that the rankings system might need adjustment to ensure fairness in the disrupted season.
Saying there was a danger the rankings could become "skewed," Murray suggested looking at a two-year rolling ranking "so the guys who did well last year and are not able to defend their points properly aren't punished."
Noting the jammed schedule envisioned for the tour's return - with the US Open to run from 31 August to 13 September followed by two elite Masters events and the rescheduled French Open - Murray said that consistent winners would have trouble committing to so many events.
The principle of defending tournament points week by week will remain. Tournament points added in 2020 that count in a player's ranking will remain for 52 weeks or until the event in question is played again in 2021, whichever comes first.
In the case of tournaments that took place in 2019 and again in 2020 during the 22-month time frame, a player can count his best result of those two, but not both from the same event.