rearing up a horse

Question
hello. in general, may i know what are the advantages of rearing up a horse?

Answer
In one word, NONE.  A horse that rears can be very dangerous, especially if being ridden by someone who is inexperienced.  Horses tend to rear when they do not have any other avenue of 'escape' - usually because the rider is putting too much pressure on the horse and holding it back. It will get to a point where it can't do anything but go up...and oftentimes over...which can be deadly to both horse and rider.