https://mathshistory.st-andrews.ac.uk/Biographies/Wald/ · PD-US

A statistician whose wartime analysis of aircraft damage became a textbook lesson in survivorship bias: military researchers wanted to armor the parts of returning bombers riddled with bullet holes, but Wald recognized that the planes that never made it back had been hit somewhere else entirely, and argued for armoring the spots showing no damage instead. He also founded the field of sequential analysis during his research career at Columbia University.