Statistical Skier

After reviewing yesterday’s sprint race in Drammen, Norway it’s time to get caught up on the distance racing action from the day before. And lucky for you I’m going to use some new graphs that I’ve been working on for a while. They’re similar to the biathlon graphs I introduced last week, with a few modifications and improvements.

Let’s start with the top four men:

This should be fairly self-explanatory, I hope. But here are some technical details if you’re into that kind of thing:

• I’ve gradually become convinced that percent back from the median skier is often a better metric than percent back from the winner (which is what FIS points are based on). Additionally, I’ve standardized these values to account for systematic differences between interval start races, mass start races, etc. Hence, the y-axis literally represents standard deviations away from the mean, using percent back from the median skier as a base measure.
• The race in question (i.e. Saturday’s race) is highlighted with a blue circle. The blue line tracks the median by season, but only for seasons with at least three races.
• Since I’ve standardized the performance measure, I had a little fun with labeling performances that are within one, two, etc. standard deviations from the mean. So one SD better than the mean is ‘Good’, between 1-2 SDs better than the mean is ‘Elite’ and more than 2 SDs better than the mean I’ve playfully named ‘Inhuman’.
• Take these ‘Good’, ‘Elite’ and ‘Inhuman’ labels with a grain of salt and a sense of humor. Even after standardizing the results, there’s still a fair bit of variation from race to race. So a result in the ‘Inhuman’ zone will typically be good enough for the win, but not always. Other times, a race can be won with a performance that is merely ‘Elite’. Generally speaking, ‘Inhuman’ performances are likely to put you in a position to win, ‘Elite’ performances will tend to put you on or near the podium and ‘Good’ performances are likely to put you in the World Cup points (i.e. top thirty). But these are just general rules of thumb.

Anyway, back to Saturday’s race. Daniel Rickardsson outclassed the field by a healthy margin, putting himself well into the ‘Elite’ performance range. As you can see, this represents one of the best races of the season for him or even for his whole career, and if you’re from Sweden you’ve got to like the way his performances are trending.

Martin Johnsrud Sundby also had a strong race, which stands out in part because of the heat that the Norwegian men have taken lately. Despite the complaints, it seems to me that Johnsrud Sundby has actually had a very strong season in distance events this year. Dario Cologna has been probably the strongest overall distance skier this season, but Saturday’s race, while just edging into the ‘Elite’ zone was probably just average for him. He’ll be expecting better over the next week at World Champs. Northug also had a strong race for him this season, despite being outclassed by Rickardsson.

Now let’s look at the top four women: Continue reading ›

I’d say someone has this freestyle sprinting thing dialed in pretty well, wouldn’t you? And what a race from Alex Harvey, much better sprint race for him. I have the heat times again, so an analysis of those will be in the works for tomorrow…

Continue reading ›

Thanks once again to Skaði Nordic for bringing you this week’s Week In Review:

• We started off with the last of the IBU World Cup races in Maine, including the pursuits and mass starts.
• I’m debuted some new-fangled biathlon results plots for race snapshots and for looking at individual skiers. The individual plots are something I’m continuing to work on (along with some XC versions) so expect to see more of those in the future.
• I spent some time recapping the North American’s performances at the FIS races in Beitostölen, Norway.
• After taking a bit of a long break, Nicole Fessel popped up at some OPA Cup races and did quite well, so we did a short look at her races.
• I added a bit to this discussion revolving around the differences between men’s and women’s race lengths in cross country events.
• Finally, I provided a brief look at the progression of FIS penalties in North American distance races over the past decade or so.

Thank God World Cup racing starts up again this weekend. It seems like it’s been forever…

There were only a handful of Americans (and no Canadians) who did the freestyle distance race in Beitostølen, Norway on Sunday, so we’ll cover them and Andrew Musgrave in one post.

First a rough look at how each performance stacked up in terms of FIS points:

By FIS points, that’s about as fast as Arritola has skied, although that’s an imperfect measure of course. Tad Elliott is typically a much stronger skater, so it’s not surprising he had a somewhat better day as well. Musgrave’s race looks ok, but not spectacular.

Before I break these down further using percent back difference plots, I need to say a few things about some peculiarities in graphing head-to-head match-ups measured by the difference in percent back. When I make these graphs, I have to make a decision about how deep in the field to go. For instance, am I really interested in how Musgrave has fared against the folks in 200th place in a race like this?

As much as I can, I try to make a reasonable decision here, but it can vary from graph to graph. If someone finished 25th, I may only compare them to the top 40; if someone finished 60th out of 130 I might go all the way back to 80th place. I also on occasion will go a bit deeper than usual for skiers who have not raced in Europe as much, in order to catch a bit more data to work with.

Long story short, since many of the Americans were higher up the results sheet today, I didn’t have to go as far down to get some decent comparisons. This means the graphs can look quite a bit different from Tuesday’s versions.

Anyway, let’s get Andrew Musgrave out of the way first: Continue reading ›