Not Quite a Chessboard: the Plain as Battlefield
In warfare the plain—a relatively large, open, and uninterrupted battleground—is like a giant chessboard. With room to maneuver, opposing commanders may have many options. They must weigh up strengths and weaknesses—their own as well as the enemy’s. Flanking, probing, enveloping, it is a game in which numbers and maneuverability are often critical. As in chess, the battle often involves the constriction and isolation of key elements of the opposing force. But like all geographic features, the picture is not quite as two dimensional as the word “plain” might suggest. We are not talking about beautifully smooth playing fields, but individual sites with their own unique characteristics. For example…Issus was fought on a coastal plain in what is now Turkey where movement was constricted on both flanks: one by the sea, the other by inland foothills. As it happened, these geographic “bookends” worked in Alexander’s favor, as they boxed in the larger number of his Persian foe and to some extent neutralized the numerical discrepancy. Some 2,000 years later General George Custer was to learn a different lesson about numbers and maneuverability on the plains of Montana. In open spaces, movement and superior numbers are king. Brought to bay on his lonely, isolated knoll, outgunned and overrun, there could be only one, grisly, outcome. He was also to learn that plains have their own wrinkles and folds. At Little Big Horn the numerous ravines (coulees) were capable of hiding significant numbers of his enemy….
— Battlegrounds, p. 13
Emphasis mine.