In 1991, Michael B. O'Higgins, one of the nation's top money managers, turned the investment world upside down with an ingenious strategy, showing how all investors--from those with only $5,000 to invest to millionaires--could beat the pros 95% of the time by putting 100% of their equity investment into the high-yield, low-risk "dog" stocks of the Dow Jones Industrial Average. His formula spawned a veritable industry, including websites, mutual funds, and $20 billion worth of investments, elevating the theory to legendary status.

Reflecting on the greatest bull market of our time,...