Show Jumping is one of the three Olympic disciplines. The sport requires a rider and horse to jump a course with up to 13 obstacles, which can either be a vertical , Oxer, a Wall, a Skinny, or a water jump. The Jumps can measure as high as 1.6 meters. The rider is penalized if a rail within a jump is knocked down or if they does not complete the course within a specified time limit. There are two main types of jumping completions, speed competitions or jump off classes. Speed competitions are one round competitions that score the rider based on the fastest time completing the course less any rail faults or rail faults can be converted to seconds. Riders with the fastest fault free time prevail. Jump off Classes, are typically two round classes. All riders that are clear, meaning no jump or time faults, return for a jump off which occurs on a shortened course of approximately 7 jumps. The fastest fault free time wins. This discipline requires the rider and horse to be in perfect harmony, as many factors such as momentum, speed, the course, and the number and length of strides taken must be combined in order to achieve a flawless performance.