This made me laugh. Language NSFW.
At Baseball Prospectus, Brandon Heipp dives into his library to trace the development and popularity of comparisons to the replacement-level player in baseball. It’s worth a read.
I know the concept is frequently cited as one of the more difficult to grasp, but I find it one of the most useful SABRy ideas to incorporate into everyday life. For food, say, I generally consider the replacement level to be what’s available at Burger King.