Eli Knight is a Black Belt under Royce Gracie and a 17 year veteran in the sport of Brazilian Jiu Jitsu. Eli also runs the popular BJJ blog "Knight Brazilian Jiu Jitsu"
science of skill blog
Tons of video clips, perspective from experts, critical breakdowns, and connections and links to everything else in the BJJ world that links into or contributes to the overall idea. Big deal stuff - definitely not a 12-minute blog post. Personally I can't find much like this by way of depth elsewhere.