At the top of the ladder, the stakes are high and the demands intense. Too many CEOs falter in the job; about a quarter of the Fortune 500 chiefs who leave their firms each year are forced out. Clearly, boards do not always get their hires right. In conducting an analysis of in-depth assessments of 17,000 executives, the authors uncovered a large disconnect between what directors think makes for an ideal CEO and what actually leads to high performance. The findings of their 10-year research project challenge many widely held assumptions. Charisma, confidence, and pedigree all have little bearing on CEO success, it turns out. Instead, top performers demonstrate four specific business behaviors: (1) They're decisive, realizing they can't wait for perfect information and that a wrong decision is often better than no decision. (2) They engage for impact, working to understand the priorities of stakeholders and then aligning them around a goal of value creation. (3) They adapt proactively, keeping an eye on the long term and treating mistakes as learning opportunities. (4) They deliver results in a reliable fashion, steadily following through on commitments.

Consulting's fundamental business model has not changed in more than 100 years: Very smart outsiders go into organizations for a finite period of time and recommend solutions for the most difficult problems confronting their clients. But at traditional strategy-consulting firms, the share of work that is classic strategy has sharply declined over the past 30 years, from 60% or 70% to only about 20%. What accounts for this trend? Disruption is coming for management consulting, the authors say, as it has recently come for law. For many years the professional services were immune to disruption, for two reasons: opacity and agility. Clients find it very difficult to judge a firm's performance in advance, because they are usually hiring it for specialized knowledge and capability that they themselves lack. Price becomes a proxy for quality. And the top consulting (or law) firms have as their primary assets human capital; they aren't hamstrung by substantial resource allocation decisions, giving them remarkable flexibility. Now incumbent firms are seeing their competitive position eroded by technology, alternative staffing models, and other forces. Market research companies and database providers are enabling the democratization of data. The vast turnover at consultancies means armies of experienced strategists are available for hire by former clients, whose increasing sophistication allows them to allocate work instead of relying on one-stop shops as they did in the past. Drawing on the theory of disruption, the authors offer three scenarios for the future of consulting.