Describe Tris's first fight

When they go to training, Tris gets a shock: her first opponent of the day is Peter. Al suggests she take a few hits and pretend to go unconscious. Tris starts thinking about Peter's weaknesses, one of Four's strategies, but she realizes he doesn't have any. During the fight, Peter goads her on before laying into her. While she's being pummeled, she sees Four get up and walk out. The last thing she hears is "enough!" before she's knocked out.