A few years back, a new proof came out regarding an algorithm to find large primes. There was a slow, perfect variant and a faster, statistical variant with a

A few years back, a new proof came out regarding an algorithm to find large primes. There was a slow, perfect variant and a faster, statistical variant with a small chance of error (like 1 in 10^20.) "Of course, this means to be really sure you have to use the slower algorithm or go through a rigorous proof. On the other hand, the probability that you'd mess up a proof is much higher than that." It was a fantastic illustration of the principle.