The Adelskalender in skating is a ranking for long track speed skating based on skaters' all-time personal records for certain distances. As in samalog competitions, the skater's time (measured in seconds) for each distance is divided in 500 metre averages, truncated (not rounded) to 3 decimal places, and the results are then added up – the lower the sum, the better. The samalog system was introduced in 1928 in Norway, replacing ranking points in the traditional 4 distance championships, and can also be used to reconstruct scores based on personal records that were set before the samalog system was invented. The classical Adelskalender consists of the Allround Championships distances: Men: 500 m - 1500 m - 5000 m - 10,000 m Women: 500 m - 1500 m - 3000 m - 5000 m Similar rankings in many other combinations are maintained by enthusiasts and available on the Internet. Calculation As an example, the points for the current leader in the men's Adelskalendern ranking Patrick Roest are calculated as follows: Caveats The Adelskalender score is calculated over a skater's entire career and not for a single tournament. Theoretically, this would make it possible for a skater to lead the Adelskalender without ever having set a 4 distance championships samalog record, or even having won - or participated in - such a tournament. Speed skating records have improved dramatically over the years due to a combination of larger participation, introduction of professionalism, improvements in training and selection, and, especially, technical developments, distorting the comparative accomplishments of skaters over time. For comparison, the ranking leader on 1 January 1900 (Jaap Eden) had a score of 202.226, "averaging" 35.6 km/h. In 1925 Oscar Mathisen led with 192.860 (37.3 km/h), in 1950 Åke Seyffarth led with 188.678 (38.2 km/h), in 1975 Ard Schenk led with 166.241 (43.3 km/h), and in 2000 Rintje Ritsma led with 150.720 (47.8 km/h). Among major technical developments were the introduction of artificial (refrigerated) 400 m ovals, the first opening in Gothenburg in 1958, aerodynamics suits in 1976 (by Franz Krienbühl), indoor, climate-controlled ovals in 1986, and the clap skate in 1996. Also, over time, more high altitude skating rinks have been built; the lower air pressure at higher altitude greatly benefits the skater's speed -the rule of thumb is 0.1 points at each distance for every 100 m of increased altitude- and world records generally are set at high altitude.