" No battle plan can anticipate all contingencies. There are always unexpected factors including those stemming from the opponent's initiative. A battle must thus becomes a balance between plan and improvisation, between error and correction.
It is a narrow line. But it is a line one's opponent must also walk. For all the balance of experience and cleverness, it is often the warrior who acts quickest who will prevail. "

― Timothy Zahn , Thrawn (Star Wars: Thrawn, #1)