The point we are making is that you can not always tell. The story I told earlier showed a green rider. Here is one with a very experianced rider.
My Dun It mare was up at the trainers. He asked if other riders could use my mare and I gave a relutant OK. These where experianced riders and reiners. Yet it took each of them some time to be able to get my mare to perform well. First year the assistant trainer showed her the combo won under $100. The next year then finished in the top 30 in the world and at one point where in the top 15. Was that b/c the rider could not ride? Was it b/c the mare was not well trained? Neither. It just took that much time for the rider to get consitant with hitting the correct cues for that mare.
Non of this you could have seen by watching a video.
It takes some time to get used to a new horse- I agree. Most horses wont perform well for a stranger based on the fact they don't trust them as the leader.. none of that could have even been changed by the person that trained the horse physically showing the rider the cues either.. I don't think that has to do with rider skill but establishment of a relationship with the horse.. and practice..