WJC Update

With a couple of races at WJC/U23s under our belts, let’s check in with how some nations are doing compared to previous years.

Some obvious trends include Finland:

Fin2

Their junior women have continued to do worse in the distance events, but have improved in the sprint. For the Russians, it’s largely been more of the same, which is a good thing (for them): Read more

WJC Preview

World Junior Championships are just around the corner, so for some perspective, let’s take a look at how various nations have done at this even historically. I’m not going to provide much commentary, just show each nation’s history.

First up the US:

Usa

Not ideal trends, I think, across the board. But junior championships can be fickle, particularly with kids (relatively) unused to travel to Europe. As for Canada:

Can

Some definite improvement for the women’s distance event, to be sure.

Now let’s look at some of the more traditionally strong nations, starting with Norway: Read more

WJC Qualification Follow-Up

In a post last week I talked about how I felt that a single early season result wasn’t necessarily a great predictor of how someone will tend to ski (on average) during the rest of the season. I feel like most people would accept that this is, in principle, generally true. Just because you pop a great race in November doesn’t mean you’ll be killing it in February.

A commenter pointed out, though, that while that person with a single great early season result might have worse results in an absolute sense for the rest of the season, they might still do better than everyone else. And that’s really all that matters if you’re selecting people for an event. That’s a good point, so I went for a somewhat more specific comparison and found that my statistical intuition wasn’t quite as correct as I had thought.

The following plot shows the the ranks of the minimum FIS point result versus the rank of the median FIS point result for US juniors:

So the people with the best minimum early season FIS point race really do tend to have the best median late season FIS point results. I was not expecting these to line up nearly this well at all.

Of course, there’s still some variability here that means it’s not perfect. (What in life is?) So you can see several instances where the person with the best FIS result in the early season only had the 4th-5th best median FIS point races for the rest of the season. But it’s much more highly correlated than I would have thought based solely on my mathematical intuition. Chalk one up for my commenters!

How Useful Is A Single Good Result?

Following up from last time, we’re still discussing the recent USSA rule changes for qualifying for WJC/U23s. Now, it’s not like USSA has a ton of options here, but I would like to point out a few difficulties with pre-qualifying an athlete using only a single result.

Being a stats guy, I always think about things in terms of variability. So when I think about a skier’s performance, I visualize it as having a distribution. An athlete’s best races come from one extreme end of that distribution, but they are necessarily fairly rare. So to my way of thinking, a skiers best race isn’t a good estimate of how well they’re likely to ski. Rather, it’s a good (-ish) estimate of how well they might ski, if we’re really lucky.

To give you some context on this, I took all the FIS point results for Americans since 2006. Then I counted up how often each skier matched (or bettered) their best FIS point race from the early season (11-01 to 12-31) during the rest of the season. I counted this separately for men/women and sprint/distance and only kept folks who had at least 4 early season results, and at least one result from the remainder of the season. Here’s what we have:

I’m not quite so interested in the sprint numbers, since FIS points are such a dicey way to measure performance for sprinting. But if you look at the men’s distance panel, what this is saying is that they ski as well (or better) than their best early season result at most once more that season around 60% of the time. The drop-off is a bit less dramatic for the women, but still it is much more likely that you aren’t going to see a race with FIS points that low for the rest of the season.

And this trend is even more stark when we focus in on just the group of skiers who’ve managed a sub-50 point race during the early season:

Granted, this simple method of counting the number of results at a certain level may obscure some things. For instance, maybe folks don’t race quite that fast ever again, but they come pretty close fairly often. That will require a different sort of analysis that we’ll delve into next week.

New FIS Point Criteria for WJC Qualification

As often happens, FasterSkier gifted me with a handy topic for a few posts to kill time with over the summer by publishing a summary of USSA’s new criteria for automatic qualification for WJCs/U23s.

For WJCs, the FIS point cutoff has been lowered to 50 for both men and women (it used to be higher for women than for men) and it can come from any FIS sanctioned race between Nov 1st and Dec 31st.

Generally, I’m skeptical of the wisdom of allowing people to automatically pre-qualify based on a single race (albeit a good one). But I’ll come back to that issue in a subsequent post. For the moment, I was curious where US juniors might be able to find races with penalties under 50 during that time of year (excluding WC races, of course). So here’s a summary of all such races that fit that bill for recent seasons:

This is showing the number of FIS races in each country within those dates with a penalty less than 50. (Of course, this doesn’t reflect how many skiers in that race broke 50 points, just that someone did.) I wasn’t expecting there to be such a big disparity between the distance and sprint races, to be honest. Part of me is wondering if this rule change will favor juniors who make the effort to get over to Europe during the fall in the hopes of popping a great race. Now that I write that, it occurs to me that encouraging juniors to “go to Europe for their points” might be part of the intent here, but that’s just speculation.

WJC Results As A Predictor Of Future Success

The never ending question! A commenter asked about this the other day, and I’m happy to oblige, despite the fact that I’ve covered this general topic several times before.

The difficulties with extrapolating from WJC results start with the fact that they comprise at most 2-3 races from a skier’s entire season. And the posts I mentioned above go into quite some detail looking at trends and correlations. And I think it’s fair to say that there is a relationship between strong WJC results and future success at the World Cup level. But there are precise relationships and noisy relationships:

Both of the panels above display precisely the same relationship between these two variables. One of them is much more useful for making predictions than the other, though. My general position is that WJC results are certainly correlated with future World Cup success, but that that correlation is so noisy that isn’t of much use on its own.

To drive this home, I thought we’d take a little trip down memory lane. Specifically, let’s roll back the clock a decade to World Junior Championships in 2002. That year 9 men and 8 women achieved a podium result at that event. I’ve sifted through those folks’ results and I’m going to show you a roughly representative sample of what’s happened to them since.

Let’s start with four of the men: Read more

WJC & U23 Updates – North Americans

I’m a bit pressed for time at the moment, so not much commentary on these. They are just the updated versions of the graphs I showed on Wednesday, giving some historical context for the results at WJC & U23’s for the US and Canada.

WJC – USA

WJC – CAN Read more

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