Spotting a falling chief executive.

• Position: Brief article

From Boards That Lead: When to Take Charge, When to Partner, and When to Stay Out of the Way. Copyright [c] 2013 Harvard Business School Publishing. Reprinted by permission of Harvard Business Review Press (www.hbr.org/books). All rights reserved.

From our several decades of witnessing more than fourscore fumbling CEOs, we have noted that, in virtually every case, warning signals were noticed early by at least one or two directors but were commonly not shared with fellow directors.

We learned of the indications in real time because alarmed board members privately disclosed their rising qualms about the CEO in the course of our work with them. The concerned directors were nonetheless hesitant--no surprise--to get the ball rolling. After all, they had helped pick the top executive, and they realized that a forced exit could be not only a career-ender for the executive but also a reputation-killer for themselves. Perhaps most inhibiting of all, they knew that the CEO often retained avid defenders among the other directors.

As a result, boardrooms frequently lack the...