I was reading a book this last week, The Blitzkrieg Legend: The 1940 Campaign in the West by Karl-Heinz Frieser (originally published in German in 1996). On page 54 it states: According to a military rule of thumb, the attack should be numerically superior to the defender at a ratio of 3:1. That ratio goes up if … Continue reading The 3-to-1 Rule in Histories