Mastering the Inner Principles of High Performance Most leaders and managers have gone about as far as they can go focusing on the “Outer Game” of looking better than their peers. To take yourself to the next level of effectiveness, you may need to pay more attention to the “Inner Game,” which has very different rules. Those who master both are virtually unstoppable. Based on 20 years of intensive one-on-one sessions with hundreds of leaders and executives from 18 countries, and recorded in his 1993 ground-breaking book, Work and the Human Spirit.