Why is 3D better?
Why is the BLACKDOG 3D system better than using normal, 2D images?
The problem with working out angles and posture just using a frame from a video is that you're trying to capture a 3D object in 2D, which can lead to perspective issues. Take this rider below, for instance.
If we were just to draw horizontal and vertical lines, as done on the right-hand image, it appears as though the rider is collapsing the right hip and raising the right shoulder. However, since we can only see one of the rider's knees, it seems quite likely that her body is twisted in relation to the camera, but we've no way of telling  for sure just from lines on the picture.
If we use the blackdogPerformance system, we can clearly see that as well as her body being twisted, her right shoulder is also twisted forwards. What's more, she isn't actually leaning to the right, or lifting that shoulder up. It's just that the perspective of the 3D shape in the 2D image made it look like she was.
Below are the positional metrics of the rider's position. The table is colour coded by a traffic light system; green is very good, orange are things that could be improved and red are things for the rider to work on. 
In conclusion, by capturing data in 3D, the blackdogPerformance system not only gives extra information over a 2D system, but is far more accurate in reporting the true posture of a rider.