This year we are discussing the Book of Martial Power (BOMP) on Saturdays
I don't have much to say about this chapter in Pearlman's book, not because it is not important - control of the center line is one of the most fundamental and important concepts. But because I just don't have much else to say beyond what Pearl an has said in his explanation.
Simply put, because most of our vital targets are located on our center line, we must protect ours, while seeking to own theirs. Additionally, because most of the important action in a conflict between two people happens in the center of the space between them, we must seek to own the center line of the conflict.
I think if I were writing this book, I would have placed this chapter before the two that surround it, because Owning The Center is the central theory, and Triangle guard and Primary Gate are primarily how we go about owning and controlling our center, their center, and the center between us.