“The energy of good fighting men is as the momentum of a round stone rolled down a mountain thousands of feet in height.”
Position determines power; a small mass from height overwhelms a large one on the flat.
Chapter 5’s finale: the energy of good fighting men is as the momentum of a round stone rolled down a mountain thousands of feet in height. The chapter that opened with dividing numbers closes by multiplying them through position. Height is accumulated advantage — every unit of it converting to force on release — and the image completes the crossbow: drawn bows store energy, but mountains grant it.
Two developers publish the same library. One ships it flat: a repo, a README, a hope. The other spends a month gaining height first — docs site, examples for three frameworks, a launch timed to a conference talk. Same code, same stone; different altitudes. The flat library fights for every star it gets; the mountain library rolls, collecting contributors and search ranking as gravity, and by year two its momentum is the moat.
Height is not luck or virality — the second developer’s month of docs was deliberate altitude, purchasable in units. The misreading treats momentum as a gift some products receive; Sun Tzu’s physics says it is a position some builders construct. And a stone at altitude still needs a push — height amplifies initiative, it does not replace it.