As the chapter opens, you see Buford's instinctiveness and experience as a commander. He can't see his enemy or the battle, but he can tell from the silences and the sounds where they are, what they're doing, and how many of them are attacking. From his own experience, Buford knows what his opposing commander should be doing next and chuckles when his opponent fails, thus giving Buford the advantage.
Buford is also able to "read" a situation well. He knows who's out in front of him now, and who will be coming soon enough. This ability allows him to plan his strategy so as to trick his enemy, use his own men to the best advantage, and buy as much time as possible. Buford's quick thinking and sharp abilities most likely saved the high ground for the infantry arriving later.
The theme of knowing your opponent is reinforced in this chapter. The opposing commanders are not unknowns. Buford knows whom he is dealing with and vice versa. This is a war of brothers and friends, not of faceless enemies.
The Rebel yell is introduced here and appears many times in the book during the battle scenes. It is a psychological tool first used by Stonewall Jackson at Bull Run. It is meant to terrify the enemy and whip the attacking Rebels into a frenzy so they are unstoppable in their attack.
