Survivorship Bias
Origin
WWII US Army. They wanted thicker armor on bombers, but extra weight grounded planes. Where to armor? Statisticians plotted bullet holes on returned bombers and proposed reinforcing the densest areas. Columbia's Hungarian-born statistician Abraham Wald disagreed: **"Where were the planes that didn't come back hit? We only see the survivors."** They needed to reinforce the *least* hit areas — those were the fatal zones.
Meaning
Don't interview only successful startups for "secrets of success" — the 99 failed founders who did the same things are invisible. Same for longevity interviews — those who died young can't answer. Survivorship bias is the fundamental danger of all retrospective analysis.
Lesson — Meeting Eastern Classics
Zhuangzi: 螳螂捕蟬 — the mantis stalks the cicada, the bird stalks the mantis, the hunter stalks the bird. Zhuangzi taught that behind what we see lies what we cannot see. Wald was the first to measure the unseen.
"殘" depicts bones + small (戔) — what remains, the residue. We see only 殘 and forget the 滅 (perished) behind it. Wald's insight: 滅 is data too. The real analysis is seeing what is not there.
