This research was started by a tweet from @realbiathlon:
That was followed up by more tweets from @realbiathlon and @Kristian_Wullf who even looked up some athlete’s Strava records:
Kristian looked up the rules and (I believe) section 3.2.2 specifies that the Women’s Sprint race should be 7,500m in length and can be 2% shorter and 5% longer as measured through the centre of the course, to accommodate the fact that measuring a racecourse to the exact distance can be nearly impossible due to local situations. Based on that information I looked up the course lengths provided by the IBU per Women’s Sprint race and compared that to 7,340m (98% of 7,500) and 7,875 (105%) for all seasons since the 2009-2010 season. Below shows the current and previous two seasons and we can see with a few exceptions the distances are within the limits but vary quite a bit from race to race:
The difference this season between the shortest (Kontiolahti, 7,432m) and longest (Oberhof II, 7,934) is 502m! And that difference is no exception, as we find when looking at the shortest and longest tracks per season:
So the differences can be big, but with a few exceptions, the course lengths are within the rules. Now how did we get here again? Oh, right, about Tiril Eckhof being a fast skier. Now that we know that every Sprint is not exactly 7,500m we cannot compare race times between races. But what we can do is convert the race time to a “7,500m-time” by dividing the race time by the actual (well, at least the provided) course length and multiply that by 7,500. And guess what?
Tiril Eckhof proves to be a super-fast skier, with a top 1, 2, 4, 9 and 19 since the 2009-2010 season. And yeah, everyone knew she was fast. But what I learned from this is the difference between races can be up over 500m, and that’s just looking at Women’s Sprint races.
The raw dashboard used for the visuals above can be found here: https://public.tableau.com/views/WomenSprintCourseLengthAnalysis/Coursetimes?:language=en-GB&:display_count=y&:origin=viz_share_link