New features: box plots and course profiles

Posted on 2020-12-10 | by

I made a few updates to the site, adding box plots to athlete and team stats pages, course profiles for all World Cup 3.3 km loops and an explanation page for the most used stats (courses and explanations can be found in the navigation bar ▷ More).

The box plot allows quick graphical examination of one or more data sets and is useful for comparing distributions between several groups or sets of data. Mathematically speaking, it offers a more robust measure than a single value, which is otherwise used on this site. A box plot is a standardized way of displaying a data set based on a five-number summary: minimum, lower quartile (Q1), median, upper quartile (Q3) and maximum. The box is drawn from Q1 to Q3 with a horizontal line drawn in the middle to denote the median.

The distance between the upper and lower quartiles is known as the Interquartile range (IQR). From above the upper quartile, a distance of 1.5 times the IQR is measured out and a whisker is drawn up to the largest observed point from the dataset that falls within this distance. Similarly, a distance of 1.5 times the IQR is measured out below the lower quartile and a whisker is drawn up to the lower observed point from the dataset that falls within this distance. All other observed points are plotted as outliers.

The data for each athlete’s box plots can be filtered by season, discipline or even more precisely with a time range slider if you select “Specified Range“. Every single stat category (all except the first five in the dropdown list) also allow a per Season series visualization (the one you can see above).

Forum member PolitiskTeoriFan made these nice looking course profiles and agreed to have them posted here. Thanks a lot for that! I created a new page where you can click through all of them. Unfortunately, visualizations exist only for the 3.3km loops right now. However, they should still be useful, even for other races. At most venues this 3.3km loop is usually just an extension of shorter loops and you can use the split time positions for orientation; they rarely change between races.

Lastly, I added a page with general explanations for all major statistics. This was previously only available (hidden) under the info icon on the seasons stats page.