socdad - I don't have an answer for you, but I can tell you they also do this at the post-season wrestling tournaments. They may also do it in swimming, but since I have never attended a post-season swimming event, I can't be positive.
With wrestling, they break it down into sessions. So, Session 1 may include the 1st Championship round and the 1st round of wrestlebacks. Session 2 might include the quarter-finals and another round of the consolation bracket, etc, etc. Each session requires a ticket. Is gymnastics set up similarly?