Having watched high-level dressage for a significant portion of my 18 years, it’s hard not to notice the rise in average grand prix scores. Being in my last year of school, I had to submit a project for every subject and, having made it my aim to reference horses in as many of them as possible, I chose to study the quality of judging and riding for my maths report. I can imagine only two reasons for the rise in average scores: either the quality of riding is getting better, or the judges are inflating the scores with time.

Since my father, David Stickland, studies dressage scores all the time, I started with a sample of 18,757 international grand prix and special tests between January 2011 and December 2016, evaluating the final scores and the variation between the judges for each test. The graph below shows the average scores over the six-year sample and the average value of the single judge precision that is derived from the standard deviation between the judges. This tells us the consistency of the judges within a test.

The trend in average score is striking — an increase of almost 0.5% per year. In the same time period, the number of grand prix tests scoring above 70% has also risen from 14% to 25%. This increase in average score value is shown by the red trend line. However, during the same period, the precision in judging is just a flat line at about 1.25%, suggesting that there’s no change in judging consistency. Furthermore, this judging consistency is completely independent of judges’ position, unaffected by different viewing angles.

The figure illustrates three things: first of all, there is a real upwards trend in scores; secondly, the flat judging precision suggests that this is not a judging effect but a real performance improvement; finally, this precision of about 1.25% per judge is remaining constant. Despite the great effort going into improving the judging system through the use of judges’ supervisory panels, judging directives and education, it looks as though we may be reaching a limit of what is possible. A change in system may be necessary.

Ref Horse & Hound; 23 February 2017