U23s: 10/15km Freestyle

Today’s U23 races in Estonia resulted in victories for some talented young skiers, Russia’s Evgeniy Belov and Finland’s Krista Lahteenmaki. In both cases their wins were fairly convincing, with Belov distancing himself from second place by 16 seconds and Lahteemaki crushed the women’s field by a full minute.

One of the difficulties in gauging performance in situations like these is that it’s hard to know how exceptional a race the winner had. Were these typical efforts for Belov and Lahteenmaki, or were they better (or worse) than usual? One way we can assess that is to look at plots of the differences in percent back between these athletes and the rest of the field, and see how today’s race compares to their past performances against these specific skiers:

Difference in percent back between Belov and the field.

The blue represents today’s race and the rest of the dots represent times when Belov has raced against some of these people in the past. Notice the short time scale here, as Belov hasn’t faced many of these racers very often prior to this season. In general, today’s race represents what looks like a typical effort for Belov against this field, compared to his other races this season.

How about Lahteenmaki’s race?

Difference in percent back between Krista Lahteenmaki and the field.

In contrast to Belov’s race, Lahteenmaki looks like she had a somewhat better race today than she has in the past, against these particular skiers. Prior this season, the difference in percent back between her and skiers in the U23 race were generally between 0 and -15. Today, none were higher than -3 and many were below -15. That suggests to me that this was a somewhat unusually good race for Lahteenmaki, which in turn might suggest that this kind of margin of victory might be difficult for her to replicate. But we won’t find out, I believe, since reports have her leaving U23s for other high level racing in Scandinavia.

Related posts:

  1. Davos Recap: Distance
  2. Davos Recap: Distance – North Americans
  3. La Clusaz Recap: Distance Mass Start
  4. Marit Bjoergen’s Best Freestyle Race
  5. Race Snapshots: Kuusamo 10/15km Freestyle

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7 Responses to “U23s: 10/15km Freestyle”
  1. xcskier22 says:

    A good indicator or at least a decent comparison of speed would be to compare Belov to skiers like Hoffman and Musgrave. Belov and Hoffman can be a great comparison, as both of them raced through the early WC’s, all the way up to La Clusaz. Musgrave only raced one WC, that was Gallivare 15km. There, Musgrave was some 30 sec behind Belov, in Otepaa he was 40 sec, so not too big of a difference. Hoffman, however, was .2sec behind Belov in Gallivare, just missing out on pts, Belov was 30th, Hoff 31st. Today, Hoffman was 1:16 out. So either Belov has really stepped up his game (which he probably has, seeing that he was top 15 last week, and has been in the top 30 at every distance WC this season), and/or Hoff has lost some spark he had earlier in the season. Musgrave seems to be skiing as well as he has earlier. Another thing to note is that it seemed to me like Belov slowed down in the last K or so, and watching the race one could see that he knew he had it in the bag and really just coasted across the line, so the gaps could have been even bigger.

  2. Brayt says:

    I think http://www.statisticalskier.com/2010/11/assessing-the-weekends-racing/ does a great job of explaining why these kind of graphs give us a better idea of how Belov skied, rather than just comparing him to one or two other athletes in the race. The comparisons to Hoffman and Musgrave are included in the Belov graph, but they’re just a small part of the picture.

    However, you bring up a couple of points that the graph doesn’t really address. If Belov coasted in the last K, then we would expect all the blue dots to shift down, and the trend line might show an above average race (instead of just about average). Also it’s hard to know how fast he was skiing in absolute terms – you can’t say where he would have been in a WC really, because this wasn’t a WC. Of course, FIS gave him 25 points, which would have put him 20th in Gaellivare (the only 15km skate on the WC so far)…

  3. Cliff says:

    Lähteenmäki is indeed going home to Finland for the national championships. The norwegians also have their national champs this weekend, and old hero Thomas Alsgaard (39) shocked the large audience by taking the bronze medal in 15 km classical yesterday. He was some distance behind Rönning and Sundby, but beat many other good names such as Röthe, Hjelmeseth and Gjerdalen. Northug didn’t start.

  4. xcskier22 says:

    Ummm, Brayt, Belov probably would have been in the top 30 or therebouts, even if he is a better classic skier. Look at his WC campaign this season. He also dominated the Russian selection races recently. As I said, he’s been in the points at every distance race, and did very well for Russia in the two relay races, racing the scramble leg. This isn’t a knock on Joran, who does an excellent job evaluating races via a mathematical/statistical method, which is beyond me, quite frankly, but its pretty easy to look at times from earlier races and see exactly what’s going on. The reason I bring the Gallivare race is because it’s a 15km skate, just like the race yesterday, it’s a similar course, not super hard, and not a whole lot of time to rest, and it was chilly, just like in Sweden. Now, obviously all of these U23/Junior skiers would have been peaking for the Otepaa races, not November racing, so that is another factor, as are conditions, course profiles, sickness, travel, etc. A lesser comparison would be to include the Davos and Kuusamo 15kms. The Davos race was 15km, but it was in classic, and Belov is better in classic than skating, and Hoffman is better in skating than classic, and the gap between them there was pretty big. The Kuusamo race was a handicap pursuit, the last day of the Ruka Triple, and that probably doesn’t do the Hoff any justice, because he didn’t have a very good start by finishing down in the sprint, so his starting position in the pursuit was much, much lower than Belov’s. I guess the pursuit coming up will really show us some really intriguing head to head racing!

    • Joran says:

      but its pretty easy to look at times from earlier races and see exactly what’s going on

      Actually, Brayt’s point (which I agree with) is that it’s actuall not pretty easy to see if we only look at 1-2 races, or only 1-2 racers. My graph does exactly what you describe (i.e. look at times from earlier races) but it uses every available race where we have a direct comparison with Belov and one of his competitors.

      This is an improvement, generally speaking, because any single racer may have had an unusually good or bad race on a particular day, which will totally ruin any comparison we’d like to make. But if we look at every available race, the good/bad races of each skier will sort of “average out”.

      To be sure, there will always be factors I can’t account for, but I strongly believe that this is an improvement over the very common practice in skiing to extrapolate based on a comparison from a single skier and a single race: “I was 10 seconds back from Skier A today, and Skier A was 20th in a WC last week, so I’m pretty close to being in 20th in a WC.” This can be amazingly misleading, IMHO. In statistics parlance, that’s reasoning from a sample size of one, which is pretty bad.

      Making guesses about where Belov would have been in a WC race is just that: guesses. It’s impossible to know for sure, although as Brayt and you both suggested, top 30 is a reasonable guess based on his results so far this season.

      Just to be clear, the point of the graph was simply that Belov’s race was right about in line with how he’s fared against those specific skiers so far this season, and Lahteenmaki’s was somewhat better. That doesn’t necessarily mean anything about how they would have fared in a WC race that day. It also doesn’t directly tell us anything about how well Hoffman or Musgrave skied that day (I could make separate graphs for them, and probably will later today).

      I hope that makes the graph a little clearer, even if you still don’t quite buy it. If you’re not understanding stuff on this site, I consider that my fault! Speak up and I’ll do my best to explain things better…

      Anyway, I appreciate the compliments (and your comments!) and no, I am not, to my knowledge, related to Al Munro Elias. ;)

  5. xcskier22 says:

    Oh, one more thing. I’ve been wondering, Joran, are you in any way related to Al Munro Elias and the Elias Sports Bureau?

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