**new to eventing procedure and competing**
...test ride? why/what/explain!?
When you have more than one dressage judge, it is standard operating procedure to have a horse and rider not entered in the competition preform the dressage test prior to the start of the actual Dressage phase. Enough time is provided between the test ride and the first competitor to allow all of the judges to get together and discuss what they saw and how they scored each movement. This is done to make sure they are all on the "same page" with the intent to avoid wide ranges in scoring between the judges.