Statistical Skier : Data based analysis and commentary on nordic skiing

Andrew Newell’s Best Season?

Most of the thunder from the US Ski Team these days comes from the women’s side, but I thought it worth pointing out that Andrew Newell is quietly on track for one of his best sprinting seasons ever:

Newell improvement

Granted, the season is only about half over, and I really, really don’t want to jinx him, but things are looking good here. Of course, Newell has historically struggled to advance past the semis and when he has he frequently has ended up towards the back of the final heat. As you can see in this graph, and this year isn’t much different. But if he continues on this track in terms of consistency, that would still be a major improvement I think.

Consider that over the past four seasons the most often Newell has qualified for the semifinals is ~58% back in 2009-2010. So far this season he’s 4 for 5. Five races is a small sample, obviously, but it also is roughly half the major sprint races Newell will likely do for the season. If he continues on this pace, he’ll qualify for the semis ~80% of the time.

Tagged andrew newell, Sprint, USA, World Cup

2013 01 15 Joran Analysis
Cross Country
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Race Snapshot: Liberec Classic Sprint

You can read a short description of these graphs here.

The men’s results:

Liberec men spr

And the women’s results:

Liberec wom spr

Tagged classic, liberec, men, race snapshot, women, World Cup

2013 01 12 Joran Cross Country
Race Snapshots
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Tour de Ski Standings Without Bonus Seconds

I’ve gotten requests to do this in the past, and did again this year. Nothing super complicated, we just add up all the bonus seconds earned by all the Tour de Ski finishers and add them back onto each person’s time. Obviously, some bonus seconds were earned by folks who ended up not finishing the Tour. Those seconds are lost forever, they aren’t reallocated to other skiers, so we’re ignoring them as well.

To get all nerdy on you, playing “what ifs” like this remind me of a common danger when interpreting the results of a multiple regression analysis. (I know, right? What a totally obvious metaphor…)

It’s tempting when looking at regression coefficients to to say things like, “If we change this variable by X units, then the response variable will change by Y units”. This is intuitive, but often misleading. The reason is that it’s rare that you can really alter one variable without others changing as well. (One exception, of course, is when you can design a controlled experiment.)

What does this have to do with Tour de Ski rankings with the bonus seconds removed (or added back on, if you prefer)? Well, the athletes likely would have raced differently if the gaps between them, or their current standings, had been different. So interpret the following with caution.

First of all, who earned bonus seconds at all?

Bonus seconds

That’s who.

If we add those seconds back onto each person’s total Tour time, we this: Continue reading ›

Tagged bonus seconds, men, tour de ski, women

2013 01 10 Joran Analysis
Cross Country
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Russian Men’s Tour Performances

Even without the somewhat dramatic ending, it seemed to me that the Russian men had a fairly strong Tour showing, and a quick graph seems to confirm this:

Rus men1

Legkov seemed to have sort of plateaued over the previous 2-3 seasons, but so far appears dramatically improved overall. Vylegzhanin had a generally off year (for him) after several seasons of steady improvement, but also seems to have rebounded. Bessmertnykh and Japarov are both younger and so we’d expect improvements from them (lower baseline).

But Tour results can be a bit funny, since a combination of the unusual tactics it produces, and the field being slowly reduced with each stage. Indeed, there does seem to be a slight trend among these guys to fall off a bit post Tour:

Rus men2

This is all distance results, with last season (2011-2012) in red. The blue trend line is fit to all the data, not just 2011-2012. Both Legkov and Maxim (screw it, I’m not typing that name again) had a cluster of strong races at the Tour and then drifted back into what for them is more “average”. Still pretty fast, mind you, but they certainly didn’t continue reeling off the results like they did at the Tour. The effect seems stronger for the two younger guys but there’s also considerably less data for them.

I’m sure they’re planning on resting up for World Championships (as is everyone else, most likely) but I’ll be interested to see if Legkov in particular can put together a full season of this sort of work, which he really hasn’t in the past.

Tagged Distance, men, russia, stage race, tour de ski

2013 01 08 Joran Analysis
Cross Country
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Race Snapshot: Tour de Ski Hill Climb

You can read a brief explanation of these graphs here.

One further note: these are based on the results for just today’s stage. Not the times reported on the FIS website (which are silly and meaningless), and not the times for just the hill climb portion of the course (which is interesting, but was sort of a pain to extract). The times reported by FIS are the “race clock times”. Each racer’s time includes the amount of time they stood around waiting to start after Kowalczyk or Cologna started. Once again, FIS manages to make the simple far too complicated and the result is gibberish. There is no universe in which the times reported by FIS reflect anything remotely resembling performance.

There are only ever two times that are needed: the time it takes to cover the kilometers skied just that day and the cumulative time for all stages. The only possible exception to this is the actual hill climb segment of the final stage, which really should be considered a split time, even though FIS rather arbitrarily decided to award World Cup points based on it but excluding the several flat kilometers leading up to the climb. Simple, right? I don’t care what crazy race format you invent for the amusement of spectators; those are the only times that should be reported next to athlete’s names.

Anyway, the men’s “race”:

Tds men climb