All very interesting, thank you.
I think most of this indeed speed, and when it comes to stealing, there's elements of instinct and skill in reading the pitcher.
But when it comes to taking the extra base, the base coaches are an underrated factor. There's a lot of info to process in a split-second when the ball's in play, and they're crucial to the team's success in this area. Tip of the cap to Messrs Borbon and Lane. Are there stats for base coaches?