International Sports Organization for the Disabled (ISOD) was created in 1964, and created the first formalized system of classification to facilitate organized sporting competition between people with different types of amputations. There were originally 27 different classes of different types of amputations. This system proved untenable because of the large number of classes. In 1976, the total number of classes was reduced to twelve ahead of the 1976 Paralympic Games. In 1992, ahead of the Barcelona hosted Paralympics, the classification system again was changed with the total number of classes reduced to the nine that currently exist today. Despite this, sometimes classes with different levels of performances would compete against each other in the same event for a medal at the Paralympic level. Small changes were formalized in 1993.