Boards Test the Numbers. The Theory Escapes.
Edition 2 — Why boards should test the theory of advantage inside the plan before they test the projections built on it.
Watch a board receive the annual strategy paper, and a pattern emerges. The financial projections absorb hours: the revenue bridge is interrogated, the margin assumptions stress-tested, the downside case probed until the executive concedes a sensitivity or two. Then the meeting moves on, satisfied that challenge has occurred. What almost never gets stated, let alone tested, is the theory underlying the numbers: the claim about why this company, in these markets, will win against these competitors and why that winning will persist. Every strategy contains such a theory, whether or not anyone has articulated it. Lafley and Martin, in Playing to Win, define strategy as an integrated set of choices about where to play and how to win, and their sharpest observation is how rarely those choices have been actively made. A plan can be internally consistent, fully costed, and theoretically empty.
There is a one-sentence test any director can run. Can you state what your company does that rivals cannot economically copy? If no one around the table can answer, the board has been auditing the arithmetic of an argument it never heard. This is the practical continuation of the case I made in Edition 1: boards approve strategy without owning it, and ownership begins with hearing the theory stated plainly enough to be examined. The good news is that the examination is not a matter of judgement, atmosphere, or strategic intuition. A theory of advantage can be tested the way any theory is tested: by checking its internal logic, locating its causal mechanism, asking what would erode it, and forcing it to make a prediction. Those four tests are the discipline of this piece, and the fourth ends in a number.
The first test is a choice: cost or differentiation, not a blend of virtues
A theory of advantage requires a position, and the oldest positional question remains the most clarifying one. Porter’s distinction between cost leadership and differentiation forces the executive to say which economic engine the strategy runs on: winning because the company can serve customers at structurally lower cost, or winning because customers will pay a premium for something rivals do not offer. The academic record on his stronger claim, that firms attempting both end up stuck in the middle and underperform, is genuinely divided. Meta-analyses and subsequent studies have found deliberate hybrid strategies that work, with IKEA as the standard example, and Porter himself softened his position in his later writing. Boards should not treat the dichotomy as a law of nature.
What the contested evidence does not rescue is the plan that altogether refuses the question. There is a difference between a deliberately chosen hybrid position, with the operating trade-offs understood and paid for, and a blend arrived at by declining to choose. The second kind is detectable in the language of the strategy paper itself. When a plan promises premium products at competitive prices with superior service and market-leading efficiency, it has listed virtues rather than made choices, and a list of virtues offers no explanation for why customers switch or why margins hold. The board’s question is simple and slightly uncomfortable: which customers will we not serve, which business will we decline, and what will we deliberately be worse at? An executive who cannot answer has brought the board an aspiration wearing the costume of a strategy.
The second test is a source: if you cannot locate the advantage, you cannot defend it
Once the position is stated, the board should ask where the advantage physically lives. Barney’s VRIO framework consists of four questions a board can put to a chief executive. Is the resource or capability valuable, in that it lowers cost or supports a price premium? Is it rare, or does every serious competitor hold the same asset? Is it costly to imitate, whether through patents, accumulated data, regulatory position, switching costs, or capabilities that took a decade to build? And is the organisation actually organised to exploit it? The questions matter because vague answers to them are the norm. Ask most executive teams to locate their advantage, and the reply is a culture, a brand, or a talented team: assets that are real but that rivals can usually match, buy, or poach. An advantage that cannot be located cannot be invested in, cannot be defended, and cannot anchor a capital allocation decision.
The fourth VRIO question deserves particular attention from boards because it is where genuine advantages quietly die. A company can hold a rare and inimitable asset and still fail to earn from it because its structure, incentives, or decision rights route resources elsewhere. The advantage exists on paper and in the data room; the organisation is simply not built to exploit it. When a board hears a persuasive theory of advantage, the follow-up question is whether the way the company is organised, funded, and measured actually serves that theory or merely coexists with it. That question tends to expose more than any sensitivity analysis.
The third test is time: what would erosion look like, and would we see it?
A competitive advantage is a decaying asset, and the decay rarely announces itself in a strategy paper. Intel is the instructive recent case. Its manufacturing process leadership was among the most defensible advantages in modern industry, protected by capital intensity and decades of accumulated capability, and it underpinned gross margins above sixty per cent as recently as 2018. The advantage then eroded in plain sight: process transitions slipped, TSMC took the technological lead, and by 2025 Intel’s gross margin had fallen to the mid-thirties while the company posted losses. The point for boards is the sequencing. The erosion was visible in the financial signature, in the margin trajectory, and in lost design wins, well before the company’s strategy acknowledged that the advantage was gone. The numbers knew first.
The board’s question is therefore prospective. It is a mistake to ask only whether the company has an advantage today; the more valuable question is what evidence would show it fading, and whether that evidence would reach the boardroom in time to act. Pricing power slipping, discounting creeping into segments that never needed it, the cost of imitation falling as technology matures, customer switching rates ticking upward, the return spread over the industry narrowing year by year. These are observable, and a board that names them in advance has given itself a monitoring role between planning cycles, rather than an annual ceremony. Erosion caught two years early is a repositioning; caught five years late, it is a restructuring.
The final test is a prediction: make the plan state the return spread it implies
Everything above concerns the content of the theory. The last test concerns its honesty, and it is where the discussion should end because it converts the theory into a number. A genuine competitive advantage has an accounting signature: returns on invested capital above the industry average, sustained over time. The base rates here should sober any board. McKinsey’s analysis of economic profit across the world’s largest companies found that the average firm earns barely two percentage points above its cost of capital, that the middle three quintiles average a trivial economic profit, and that the top fifth captures roughly ninety per cent of all the economic profit created. A company whose plan assumes top-quintile economics is claiming membership of a small club, and the odds of moving into it from the middle are around one in twelve over a decade.
Three questions apply the test. First, the premise check: does the advantage the plan claims show up in today’s returns? If the strategy proposes to extend an existing advantage while current ROIC sits at or below the industry mean, the plan is built on an asset the accounts cannot find, and the board should hear why the theory believes something the numbers do not. Second, the prediction: ask the executive to state the return spread the strategy should produce and by when. Lafley and Martin’s device is the right instrument here: work backwards from the claim and ask what would have to be true, about pricing power, cost position, and imitation, for that spread to materialise. Hidden assumptions surface quickly under that question. Third, the falsification criterion, agreed in advance: what evidence, on what timeline, would count as the theory failing? A spread that fails to open, or begins to narrow, is not noise to be explained away in next year’s paper; it is the theory being refuted. A theory whose disproof cannot be specified is not a theory, and a board that fixes the criterion before approval has made the strategy accountable in a way no amount of subsequent scrutiny can replicate.
What the board should now demand
The practical changes are modest in cost and significant in effect. Every strategy paper should contain the theory of advantage stated in plain language: the choice made, the source located, the defence explained. The current and predicted return spread relative to the industry should appear in the annual reporting pack and be tracked against the claims the strategy made when it was approved. And at least one challenge session in the cycle should be structured around the four tests rather than the P&L bridge, because a board that spends its scarce challenge time on the projections is testing outputs while the inputs pass unexamined. None of this requires new advisers or a longer away-day. It requires the board to insist that the theory be stated, and then to treat it as the executive’s most important testable claim.
The numbers in a plan are downstream of the theory. If the theory is sound, the projections are forecasts; if it is absent, they are wishes with spreadsheets attached. A board that tests only the numbers has delegated the one judgement it exists to make.
If this is the kind of examination you want your board’s strategy discussions to survive, subscribe to Strategy in the Boardroom. I write for directors, executives, and advisers who believe a strategy is a theory the board must test, own, and hold to its own predictions, week by week and cycle by cycle. Future editions will take the next steps in that discipline, starting with what capital allocation reveals about the strategy a company actually has.