@june oh ok it's from world war 2 and it was a study of where planes got shot the most, and based on this they reinforced those spots with more armor, completely missing the fact that this data came from only planes that made it back to base, which is why hits to the engines and cockpit are not represented in the data set. it's a commonly used example of survivorship bias, which is the sort of thing you're doing. just because you got lucky and didn't inject unknown particles or crystals into your thigh muscles and get an abscess doesn't mean it's safe to keep doing that