Also, the whole thing about "velocity" is just weird. It's as if some marketing goon heard the word "Velocity" and decided to over load the term in a manner that does not mean Velocity in the mathematical sense. Like in Calculus... the velocity curve is the first derivative of the linear graph, and the accelleration curve is the 2nd derivative. And for that matter, who cares about velocity, we have always wanted accelleration which sorta yields velocity. The problem with velocity, it's a dumb idea, because if I drop a rock from a tall building, it builds velocity as it free-falls down, and so it goes -- you have differetn kinds of velocity, but you only really have one kind of accelleration.

Another issue, as the blog points out, story points are a simple scallar number, and you cannot easily say how that sum is factored into risk, complexity, effort, etc... So why even have it? Clearly a story needs to be a kind of vector with these properties (risk, complexity, effort...) set to possitive or negative values, and then do the typical vector math to plot the dirrection and magniture of the story in the n-dimensional space... Then, one can actually calculate stupid ideas like velocity or accelleration to speak in the language of project/program managers.

Ultimatly the managers need a way to quantize the units of work done by development staff to better plan, and that's understandable, yet really hard. I think putting the cart before the horse is usualyl a dumb idea, and things should go back to measuring performan after the work is done, instead of estimating performance before work begins. Nobody wants to commit to a performance contract for each and every task ad nausium, and thats what happens durring sprints.