In August of last year, I wrote an article on this website about “Impact of external factors on shooting performance in biathlon“. I was still limited to using hand-scraped race data of women’s sprint races only and had to work with the restrictions of using weather data of which the quality was unknown but likely not very high (“all these measurements should be taken with a grain of salt; how accurately are they measured, it’s only on one measure location, some measurements are qualitative”). For shooting performance, I used Shooting time + Penalty time, and I came to the conclusion that for impact on shooting performance the most important indicators are the combination of maximum wind speed and change in speed and visibility, and that course conditions had limited impact.
Then on RealBiathlon the article “Is Oberhof the most challenging venue on the World Cup tour?” appeared at the end of last year, which looked at venue hit rates and average shooting times over the years, as well as venue course difficulty and median ski speed, and provided this data to its subscribers. From this data, I only used venues that were still in use in the 2016-2017 to the current season period, and that had 40 races or more:
This clearly shows basically for all factors (ski speed, shooting percentage, and shooting time) that Oberhof is the least favourable venue for athletes from a performance perspective.
For weather, I’m going to focus on wind specifically. Due to the qualitative and somewhat inconsistent weather data I don’t feel comfortable enough about this data to draw any conclusions (as I also concluded in August). Here are some combinations of Sky values at the start, after the start and at the finish. Depending on when athletes start they can have very different experiences, and remember the sky value comes from one location at the venue.
So let’s look at wind again then, now that we have a lot more and better data for men and women, all non-team races and going back to the 2016-2017 season:
As with the previous analysis we can see from the above that Wind Strength correlate strongest with Shooting performance, with roughly 12% of the change in shooting Performance being attributed to the maximum wind strength, and about 6% to the change in wind strength. The wind direction has no statistically significant impact on the shooting performance.
The table below compares the measured values from August 2020 to this article. There are some changes, but the top two variables remains he ones statistically significant although their impact changes somewhat:
| Correlation | August 2020 | Jan. 2021 |
|---|---|---|
| Max. Wind Strength – Shooting Performance | R2=0.356 | R2=0.121 |
| P=0.0017 | P<0.0001 | |
| Change in wind Strength – Shooting Perf. | R2=0.043 | R2=0.063 |
| P=0.043 | P=0.0006 | |
| Change in Wind direction – Shooting Perf. | R2=0.3 | R2=0.0015 |
| P=0.189 | p=0.603 |
Also the same as in August is that the correlation between Maximum Wind Strength and Change in Wind Strength is strong, be it a little less at 61% but that the Change in Wind Direction does not correlate much with the Maximum Wind Speed (just over 2% with a significance of just below 5%).
If we plot the average change in wind speed (vertical) and average maximum wind speed (horizontal) for all locations since the 2016-2017 (I lexcluded PyeongChang, Sodier Hollow and Tyumen as they are not regular event locations) we can see which venues have tough wind-conditions, and – as we know now – have tough shooting conditions:
In some cases there is clear overlap with the chart shown at the beginning of the article (Oberhof) but almost all venues do not align between the two charts. This is where we need to remind ourselves we are talking about 36% impact at the most, which leaves 64% impact for other variables.
In the end I was happy to see the wind charts that now used much more data produced similar results, but dealing with weather data remains risky when it comes to drawing any conclusions.