A third period gets wrestled only if there were the same technical points scored in the 2 periods.

Say wrestler A techs wrestler B 1st period. Then, 2nd period wrestler B beats wrestler A 4:2. Wrestler A still wins because he teched while wrestler B won his period only by a decision.

Say wrestler A wins 4:2 1st period. Then, wrestler B techs wrestler A 2nd period. Wrestler B wins.

3rd period gets wrestled only if both wrestlers won their periods by a decision or a tech.