Sorry, In The saddle, you are wrong on how dressage scores are given. Tests are divided into movements. The intervals leading up and away from a movements are scored within the movement. So A, enter trot- X halt salute - proceed trot , gets 1 score ; for the enter center line the transitions, halt and trot after the halt. next move, turn off the center line to the circle at “B” will get another score; not only for the circle but for the trot to the “B” marker and after, and for the quality of the corners.
Quality of bending through the corners is where many riders loose points on their tests. The hardest part for a lot of novice riders to get is to who to ride the whole test, not just the movements. There are a few movements that get a score for just the corner, I think one is in the GP Special.
Any disruption of the horse before or after a specific movement is judged within that movement box.
Most judges have a half way point where they consider one movement over and the next one starting. This is usually the center line, corner or through “X”. Sometimes movements blend one to the next, such as the 2nd level shoulder in /circle /haunches in exercise. Three scores. Sometimes a score box will include several “movements” that only get one score.
The horse is being judged from the moment it enters A and until the salute at the end. I saw a FEI rider enter at A and get eliminated after 2 steps because she forgot to drop her whip ( when they could not carry them)
Behavior problems are weighed differently. The rules spell it out. Young ( training level) horses are usually permitted a minor “behavior” waver. Some will look out of the ring during the halt, some might shy at the judges booth the first time past. Judges are permitted to “ignore” a minor booboo. If they become persistant with in the test, however, points will come off within the movement score and below the line under the submission score and sometimes under the riders score.
Major blow ups, esp on a more advanced horse will not be tolerated. Any delay of progress of 20 seconds is cause for elimination. Once a horse is out of training level shys, spooks, loss of attention and other misbehaviors that are not obviously with reasonable cause ( that dog that ran into the ring, the judges booth door that blew open) are not well thought of. Points will be lost in submission.
Judges have the power to stop a test if a major disruption out side the ring causes disturbance to the horse. This happens rarely. When it does it is usually a loose horse cannoning around.
