The power grid is a huge restaurant where thousands of 'dishes'—potential accidents — threaten to be served every minute. Checking every plate fully would take hours, and a quick glance sometimes misses danger, like invisible mold on cheese. The method of von Neumann (who devised a way to catch card cheats by checking only a fraction of the deck) suggests a different path. First, a quick filter discards obviously safe cases. Then, from the rest, a random sample is taken and rigorously tested against the standard model of the grid. Using an uncertainty estimate, the system guarantees: with 99% probability, the share of missed defects won't exceed the limit, like in a kitchen where the acceptable spoilage rate is under 1%.
A final precise analysis, like a lab spectrum test of a dish, reveals hidden overloads where a superficial glance fails. It's based on random processes of Markov and distributions of Gauss.
A single broken wire can trigger a chain reaction of overloads, like an overturned pot flooding the whole stove.