The World Ranking Scheme of TrailO began operation in 2018, which used a scoring method of 0-15 for each competition, the lower the better. As this method is abnormal, in order to unify the scores of all orienteering disciplines, the scheme was changed in May 2023 to be 10-1000 for each competition, the higher the better, and applied retrospectively to 1 January 2023. Between January and May 2023, World Ranking Event results in the original scoring (including Hong Kong Trail Orienteering Championships 2022 (PreO)) have been amended to the current scheme.
After the change of the scoring method, due to the difference in the PreO and TempO formulae, the original scores of 0-15 cannot be mapped to the current scores of 1000-10. Using the top ranked athlete back then, Antti Rusanen, as an example, on 31 December 2022, his best 6 results included 4 PreO and 2 TempO races, however, after the new scoring became in force on 1 January 2023, his best 6 results included 5 PreO and 1 TempO races instead. At the same time, Juha Hiirsalmi, who was ranked the 2nd originally, dropped to the 7th in the new scheme.