@ThisIsMissEm It is an example of survivorship bias. An RAF or American Air Force analyst surveyed bombers for damage and created a map of the areas the planes were hit most often. These areas were then armoured up for protection. The problem is that by definition the "hit areas" were the least damaging. Any serious hits resulted in the loss of the airplane so that was an airplane that wouldn't be surveyed. The worst hits were not being mapped.