Yes they do use hackamores in grand prix events. Rodrigo uses this exact hackamore on Baloubet du Rouet, but that isn't the reason I want it. I haven't found any bad reviews on it like I have on the other hackamores. There is one other that is very inexpensive that has the same set up as the one that I want. The only reason I haven't gotten it is because the reviews said that it broke easily on them, also I bought jump cups from the same website that has it and they came to me broken and I had to have them welded back together. Thanks to you guys I think I will buy that one first before getting the Pessoa one, just to see if it works for her. Then if it does then I can still use it on my gentler mare, until something happens to it.