Clayton Christensen opens The Innovator's Dilemma with the puzzle motivating his entire research project: why do well-managed, successful companies — companies doing everything conventional business wisdom suggests they should — repeatedly fail to maintain their market leadership when facing certain types of new, disruptive competitive technology.

Christensen's foundational research puzzle:

• He observed that industry-leading companies frequently maintained excellent management practices — closely listening to existing customers, investing in sustaining technology improvements existing customers valued, carefully allocating capital toward their most profitable existing business lines — while still losing market leadership to new entrants offering initially inferior, lower-margin alternative technologies
• This pattern directly challenged conventional business wisdom, which typically attributes market leadership loss to poor management decisions, since Christensen's research specifically examined cases where established companies were, by conventional measures, actually managed quite well
• This foundational puzzle sets up the book's overall project: developing a theory explaining how genuinely good management practices, applied consistently and rationally, can nonetheless produce this pattern of disruption and market leadership loss under certain specific, identifiable circumstances

This foundational framing distinguishes Christensen's approach from more simplistic explanations attributing disruption purely to management failure or complacency, instead examining the systematic, structural reasons well-managed companies remain vulnerable to disruptive innovation despite, and sometimes even because of, sound conventional management practice.