Let's face it: some horses are just not suited for certain jobs. Making an honest assessment of your horse's abilities well before you attend any horse show will allow you to both properly prepare for the challenges that you will face at the show while preventing disappointment in case your horse doesn't measure up against the competition.
In order to prevent any confusion, I will outline the differences between hunters and jumpers.
Hunters are judged subjectively on their movement, manners and jumping style. The ideal movement is described as "daisy-cutter": long, sweeping strides with as little knee action as possible. The horse should move in a relaxed, round manner and should be quiet and rhythmical. A good hunter will form a round bascule over the jump, stretching its neck forward and down and lifting its back. The knees should be even and square.
The horses are expected to put a set number of strides (usually based on a 12' stride) in each line of jumps. Lead changes must be of the flying variety since breaking to trot is a major fault.
Hunter turnout is very conservative with fitted saddle pads, braided manes and no bright colours.
Jumpers are judged objectively on time and speed. Style does not count as long as the job gets done. Jumpers must be able to turn well and go more forward than hunters. A good jumper should be able to compress or lengthen its stride in order to cope with challenging questions in the course design.
Generally speaking, first and foremost the rails need to stay up and then speed will determine where each horse places amongst those with the same number of faults.
While they are not judged on style, jumpers benefit from being rideable and using themselves well. An unbalanced or unrideable horse will often result in many faults.
Now is the time to ask yourself where your horse fits in. If your horse is quick and hangs its knees, it will probably never be a top hunter. If your horse is very slow and spends a lot of time in the air, it may not be quick enough to get top ribbons in the jumper ring.
Taking the time to assess your horse can keep you from being disappointed by a lack of results in the show ring later on. There is nothing stopping you from competing with a horse that is not likely to win (just being there to compete can be fun in itself), but knowing that ahead of time will let you know what to expect when the results are called out at the horse shows.