ELI5: Explain Like I'm 5

Probabilistic method

Oh, great! The probabilistic method means using tools from probability to understand things that might not seem very certain or predictable. Let’s say we want to know something about a situation that is extremely complicated, and we can’t figure it out using any other methods. We can use probability to get a general sense of how likely different outcomes are, even if we can’t say for sure exactly what will happen.

Think of it this way - you have a jar full of jelly beans, and you want to know how many of them are blue. You could try to count them all, but that would take a really long time. Instead, you could take a random sample - say, 10 jellybeans - and count how many of them are blue. You can then use that information to estimate how many blue jelly beans there are in the whole jar. You might not get an exact answer, but you’ll get a pretty good idea of what to expect.

In math, the probabilistic method works in a similar way. You use probability to estimate outcomes, even when you can’t calculate them exactly. For example, let’s say you have a graph with a lot of different edges (connections between points). Trying to figure out all the details of how the graph looks could be extremely difficult, but you can use probability to estimate things like how many big groups of points there are, or how long the longest path is.

Overall, the probabilistic method is a really useful way to get a general sense of a complicated system, without having to figure out every single detail. It’s like taking a shortcut that still gets you to the right answer!