Karpathy’s March of Nines shows why 90% AI reliability isn’t even close to enough

“When you get a demo and something works 90% of the time, that’s just the first nine.” — Andrej KarpathyThe “March of Nines” frames a common production reality: You can reach the first 90% reliability with a strong demo, and each additional nine often requires comparable engineering effort. For enterprise teams, the distance between “usually works” and “operates like dependable software” determines adoption.The comp…