The International Association of Athletics Federations (IAAF) has launched its official world rankings system on a trial basis.
Designed to incentivise top athletes into supporting the best competitions, the rankings will eventually help determine qualification for major events.
However, they will not be used for entry to this year's IAAF World Championships in Doha.
The launch will enable athletes, member federations and key stakeholders to see during the 2019 season how the system works in practice.
"For the first time in the sport's history, athletes, media and fans will have a clear understanding of the hierarchy of competitions from national through to area and up to global events, allowing them to follow a logical season-long path to the pinnacle of athletics' top two competitions," said IAAF President Sebastian Coe.
"The IAAF world rankings will drive and shape the global competition system including entry into future major championships and enable everyone in and interested in our sport to know who is number one in the world."
Following a 10-month period of consultation with stakeholders from across the athletics family, the final rankings system has been designed to balance the wide-ranging feedback and competing needs of those within the sport.
Athletes' positions in the IAAF world rankings will be based upon the points they score, determined by their performance and place, and the importance of the competition in which those results are achieved to the IAAF global calendar.
According to an IAAF release: "IAAF has undertaken to create a global ranking system where athletes score points based on a combination of results and place depending on the level of the competition in which the result is achieved.
"The ranking is then based on their average score over a certain number of competitions in a defined period of time.
"The basis for the ranking method has been developed with Elite Ltd (All-Athletics) whose founder, Dr. Bojidar Spiriev, developed a first set of rankings already back in 1979.
"The calculation mechanism, as well as the different categories of competitions and the placing scores awarded for each category, can be found under the tab world ranking rules.
"Because of their nature, the world rankings can also be used as a tool to compare multiple performances across a range of competitions.
"By applying standardised compilation methods, it is therefore possible to evaluate the comparative quality of the participating fields at competitions of the same type and to produce competition performance rankings.
"These are available in the specific tab where there is also a link to the ranking rules which apply."
The world rankings will be issued every Wednesday.