Predicting World Cup FIS Points (con’t)

On various occasions I have looked at FIS point race penalties, in a very general, roundabout way.  Most recently, I looked at whether the FIS points you get in a non-World Cup race accurately reflect what you would have scored if you had raced in a World Cup race.

The answer appeared to be: kind of.  At least for the OPA Cup and Scandinavian Cup circuits.  Specifically, we do see roughly the sort of relationship we’d hope to, though there is considerable variation from skier to skier.  This is an important example of the difference between something being true on average, and being true absolutely in every case.

One interesting extension of that post is to look at top North American races and see if we find a similar relationship.  The methodology is exactly the same, only the races I’ve used have changed.  I looked for skiers who did at least one “minor” race (Super Tour, Nor-Am, US/CAN Nationals, Continental Cups) and at least one “major” race (World Cup, Olympics, World Championships) in a single season.

This leaves us with an even smaller collection of athlete/season data points than before: generally only 5-15 skiers per season.  We also have the same problem of small numbers of races.  A skier may have done a bunch of domestic racing and then only one World Cup in a season.  So all the same caveats apply.

Here’s the graph:

As you can see, there are many fewer data points here.  However, the end result is basically the same.  The overall correlation between median FIS points has, if anything, improved over the OPA/SC cup case.  However, the high degree of variability has remained as well.

How To Win A Medal (Or Come Kinda Close)

Another interesting data-centric post appeared over at NCCSEF, and when it comes to data, I just can’t help myself but comment.

This time we’ve got some slides that seem to be trying to draw a relationship between WJC results and winning a medal at (I believe) the Vancouver Olympic Games. We’re only shown the (partial) results for six skiers, so I’m not sure what exactly the lesson is supposed to be.

We seem to be mixing sprint and distance results together as an indicator for future success. That seems strange to me, but I’m certainly not an expert in that sort of thing. We’ve also selected a curiously successful subset of Olympic medalists to examine. Absent is Pietro Piller Cottrer, who’s best (and only) result at WJC was 32nd (admittedly, a long time ago). Also missing is Aino-Kaisa Saarinen who’s WJC results were 15th and 23rd. How about Tobias Angerer (WJC: 18th, 26th, 28th)? On the other hand, we are shown Marcus Hellner, who’s WJC results were good but not spectacular: 15th and 21st.

The further information provided at the bottom regarding time to an athlete’s first podium also contains mostly skiers who achieved this feat fairly young, but then also two who did not (Gaillard and Rickardsson).

What am I to learn from this? That the right path is to podium at WJC (Northug), except when it isn’t (Bjørgen, Haag)? That the right path is to be successful early in your 20’s on the WC (Northug, Harvey), except when it isn’t (Gaillard, Rickardsson)?

When I read stuff like this, I’m left feeling mostly confused, like I’ve been presented a bunch of data, but that no one has gone to the trouble to transform this data into information. The reader is left alone, drifting in a sea of numbers, wondering what exactly was the author’s point.

I’m absolutely not going to argue with the idea that skiers who show considerable promise early on are more likely to develop into successful WC skiers. Indeed, I’m less interested in the nuts and bolts of what results mean at a given age than I am in effective and clear presentation of data.

I’ve written about connections between WJC results and medal on another occasion and I tried to emphasize the fact that when you look at all the data, there’s certainly a connection, but the different paths that skiers take toward success can vary so much that it’s difficult to create many useful generalizations just from the data.

But let’s revisit this idea with a few simple approaches and see if we can organize the data in a way that’s informative (and maybe interesting too!). First, I’m going to broaden the scope from medals to top ten results at either Olympics or World Championships. The problem with looking only at medalists is that there are just too few of them. Much can be learned by imitating a single good skier, but there’s always the danger that what worked for them only worked because of something unique about them, rather than having stumbled across some universal truth of skiing.

Let’s tackle the connection between WJC results and whether or not someone achieves a top ten result at the Olympics or World Championships. I fit a simple model (actually, not so simple; no OLS regressions here!) and plotted the model’s predictions for the probability of a top ten result at a major championship based on that athlete’s best result at WJC (sprint or distance): Read more

Guess The Medalists!

Another guessing game, this one based on a misunderstanding of a previous one.  This time, I’ve graphed FIS points vs. date for five skiers up to an Olympic race where they will all race against each other and finish in the top five.  Your job is to identify the medalists and for bonus points the order of finish for all five.

And here’s a version that’s zoomed in to only the 30 races just before the Olympic race in question:

Read more

Prediction Game: Results!

Back on Monday I posted the graph shown below and posed a question:

It turns out I didn’t ask my question very clearly, because I had to keep updating the post with clarifications.  So that’s my fault.  Maybe this time I’ll do better.  What I did was plot a part of the time series of FIS points for these five women.  The x axis is time, and the large white grid lines represent around five years.  So the “next race” for these five skiers will not be the same race.  They’re not all about to race against each other.

My question was for you to pick which of the five would have a top three result in a WC, WSC or OWG in their respective next races.  I provided a few more pieces of information: at least one of the women will succeed (so the answer isn’t “none of the above”) and the one(s) that do, it will be their very first career podium.

Here’s the answer in graph form:

Read more

Prediction Game: Who’s Gonna Podium In Their Very Next Race?

Five mystery skiers, all women.  For each skier, their very next  (distance) race is a WC, OWG or WSC race.  Which of them are going to finish on the podium (top 3) in their very next race?

To make things a bit more challenging, I’ve omitted the x axis labels (which is date, not age), so you can’t work backwards from what season I’ve stopped each graph in.  Update: Just to clarify, the tick marks on the x axis represent a time gap of about five years. But I will tell you that the races that I have plotted aren’t limited to major international competitions (WC, OWG, WSC); I’ve plotted every distance result I have for each skier.

Update2: Apparently I can’t seem to write very clearly this morning.  It should also help to know that the “next race” each skier is about to do is potentially a completely different race.  So it’s not like they (or any of them) are about to compete in the same race against each other.

I will also tell you that there is at least one skier who podiums and that for those who do podium, it’s their first career podium.

Leave your guesses in the comments!

I’d say I’m going to post the answers tomorrow, but my traffic probably isn’t high enough to warrant that quick a turnaround.  How about we leave this open until Friday?

Update 3: Yet another reader requests a hi-re version of the graph.  Honestly, I don’t think it will help much.  But I am nothing if not responsive to my readers (click through for full version):