More About Back Forcing
Normally, undoing the last match and stretching the rule will solve most of your pairing problems.
Sometimes, you will have to back out of the last two matches you've made in order to find a way to match everyone.
It is even possible that you may have to back up three or more levels in order to match everyone. You just have to keep trying until you find a combination that works.
In rare cases, it will be impossible to match everyone. (The rulebook says that this can happen when there are only four wrestlers left and nearly everyone has wrestled against everyone else.) In this case you are allowed to give a bye to two wrestlers.
Trivia of the Day:
Computer programmers sometimes use a similar method to solve problems, only they call it backtracking.
The classic backtracking example is figuring out how to place eight chess queens on a chessboard so that none can capture any of the others.