Sun Tzu said it better; VI, 'Weak Points and Strong':

1. Appear at points which the enemy must hasten to defend; march swiftly to places where you are not expected.
2. An army may march great distances without distress, if it marches through country where the enemy is not.
3. You can be sure of succeeding in your attacks if you only attack places which are undefended. You can ensure the safety of your defense if you only hold positions that cannot be attacked.
4. Hence that general is skillful in attack whose opponent does not know what to defend; and he is skillful in defense whose opponent does not know what to attack.

I think Willie Keeler said it first. (I think I saw Babe Ruth, played by John Goodman, say it in The Babe, but that was a long time ago.)