“If he sends reinforcements everywhere, he will everywhere be weak.”
Spreading defense to all points makes every point weak; force the opponent into that dilemma.
Chapter 6 states the denominator problem: if he sends reinforcements everywhere, he will everywhere be weak. The converse is the instruction — a threat credible at multiple points forces the defense to divide itself into weakness. Note the economy: you need not be strong everywhere; you need only be ambiguous everywhere, and strong at the one point you actually choose.
A challenger brand runs believable signals in three channels simultaneously — retail expansion rumors, an enterprise sales hire, a patent filing — each cheap, none conclusive. The incumbent’s quarterly review spreads its response budget across all three. The challenger’s real move, the fourth one nobody saw, enters a market now defended by a third-strength team. The dilution was purchased with press releases.
Forcing dispersion is not spreading yourself — the challenger concentrated its real effort in exactly one place while manufacturing ambiguity about the rest. The misreading runs the play on itself: signaling everywhere and building everywhere, strong nowhere. Sun Tzu’s version has exactly one true front, and the discipline is never losing track of which one it is.