15. A Tactical Innovation That Revolutionized Warfare
The Greek norm was to place the best troops at the right side of the line. As such, it was rare for the best troops of both armies to come into contact with each other. Epaminondas changed that, and put his best troops on the left side of his line, directly opposite the Spartan elites. Then he introduced two innovations that revolutionized warfare. First, he abandoned the norm of lines of a uniform depth – usually 8 to 12 men deep. Instead, he stacked the left side of his formation 50 deep, by thinning the rest of his line. That is, he concentrated force at the decisive point. Second, rather than advance in line abreast, Epaminondas echeloned his army so that his powerful left was the first to reach the enemy, and his weaker right was the last.
