[thedevindevops]

Tough one, I'd have to say:

45% http://setosa.io/ev/markov-chains/

30% https://en.wikipedia.org/wiki/Markov_chain

25% Youtube

[snakeboy]

The wikipedia page for Markov chains is really one of the best wikipedia pages I've ever seen for a technical topic.

Covers a ton of ground, and gives concrete examples to motivate the ideas.