In 1889, one could only win the World Championships by winning all three distances. If no one won all three distances, no winner would be declared. Silver and bronze medals were not awarded.
In the years 1890-1907, one could only win the World Championships by winning at least three of the four distances, so there would be no World Champion if no skater won at least three distances. Silver and bronze medals were never awarded.
In the years 1908-1925, ranking points were awarded (1 point for 1st place, 2 points for 2nd place, and so on); the final ranking was then decided by ordering the skaters by lowest point totals. The rule that a skater winning at least three distances was automatically World Champion was still in effect, though, so the ranking could be affected by that. Silver and bronze medals were awarded now as well.
In the years 1926-1927, the ranking points on each distance were percentage points, calculated from a skater's time and the current world record time. Apart from that, the system used was the same as in the immediately preceding years.
Since 1928, the samalog system has been in use. However, the rule that a skater winning at least three distances was automatically World Champion remained in effect until (and including) 1986. It was abolished as a result of three-distance-winner (and thus World Champion) Rolf Falk-Larssen having a worse samalog score than silver medal winner Tomas Gustafson in 1983.
^Pajor used to skate for Hungary until he defected in 1949. From then on the ISU allowed him to participate as an independent skater representing the ISU as he did in 1951. In 1952 he represented Sweden at the European Allround Championships in Östersund in Sweden winning the bronze medal in the overall standings.
^Until 1995 Veldkamp skated for the Netherlands. From 1996 he skated for Belgium in order to avoid having to participate in Dutch qualification trials for the major tournaments.