The Cant-Wont Test
The sustainability test for a How to Win: can competitors not copy your advantage, or won’t they? If neither holds, you have a head start, not a moat.
Can't: replication is genuinely out of reach. Proprietary assets, compounding data, a regulatory position, or capability depth built over years that a rival cannot compress into a budget cycle. Won't: rivals could copy you, but doing so would contradict their own strategy or economics. Four Seasons' long-tenured, heavily invested staff is copyable in principle; a cost-led competitor will not copy it, because doing so would break their own model. Both are real protection. Knowing which you hold tells you how much time you have.
The deep mechanism behind "won’t"
The strongest "won't" is not reluctance, it is structural: integration. Any single visible choice is imitable. A reinforcing system of choices requires the copier to become a different company, and that is the one price well-run rivals refuse to pay, because it means abandoning what currently works for them. This is why integrated strategies age well and clever features age badly.
Reading the result
Passing the Opposite Test but failing this one is a specific, common diagnosis: you made a real choice, and it will not stay yours. Expect convergence, then price competition, the endpoint of Operational Excellence Is Not Strategy. The finding is not "do nothing"; it is "bank the head start and build the next layer of protection while rivals are still copying the last one".
The temporal answer
Our own research adds a third answer to Martin's two. Across the 500-plus businesses in the ZOKRI compound advantage research, the deepest "can't" we observed is temporal: a lead that grows while it is being copied, because the advantage is designed to compound. The copy is accurate the moment it is taken and obsolete shortly after. That argument, and the tests for whether an advantage genuinely compounds, live in Compound Advantages.
How this connects to OKRs
The test disciplines what a company builds with its quarters. A capability-building OKR aimed at something rivals can copy next quarter is maintenance dressed as strategy; aimed at deepening a "can't" or widening a "won't", it is the compounding kind. Asking which, before the quarter starts, is a ten-minute conversation that redirects entire roadmaps.
One line to keep: Before you build, ask whether it deepens a can't or widens a won't; if it does neither, it is maintenance in a strategy costume.
Our synthesis of Roger Martin’s published work, sources credited. Read the originals: they’re excellent.
What is the Can't-Won't Test? +
A test of whether an advantage is protected because rivals cannot copy it, or because they will not, since copying would break their own model. Both are real protection; knowing which you hold tells you how much time you have.
How does it change what we build? +
A capability-building OKR aimed at something rivals can copy next quarter is maintenance dressed as strategy. Aimed at deepening a can't or widening a won't, it compounds. Asking which, before the quarter starts, redirects whole roadmaps.
Reading about method is not the same as running it. We install this system and build the capability that stays.
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