Books like StrengthsFinder 2.0 have helped leaders discover their strengths - but they stop there. The Sindells argue that focusing only on your best abilities neglects a vital development opportunity. They show how to identify hidden strengths that can be quickly elevated into full strengths with attention and focus.

Working mainly on your strengths can ultimately make you weaker, they argue. You need to continually add new skills, not rely on what you're already good at. And while most people assume that means they should try to turn their weaknesses into usable skills, the Sindells say that it takes too much time and effort: The ROI just isn't there. It's in the neglected middle skills, neither strengths nor weaknesses, that the most potent development opportunities lie. They're close enough to being strengths that putting your energy there can offer a powerful payoff.

Using assessments, exercises, and case studies, the Sindells help you identify your most promising middle skills and create a plan to turn them into strengths. In today's work environment, not growing and stretching yourself translates into lack of innovation, stagnation, and obsolescence. Relying upon strengths is like relying upon training wheels. At a certain point you need to take them off in order to improve and grow.