Motley Fool co-founder David Gardner has a remarkably good track record in the market. Does he only pick winners? Heck no. But does his portfolio of stocks outperform the market fairly consistently, and over the long term? Oh yes, and by an appealing margin. (Feeling skeptical? Look deeper into our website and see for yourself -- the man keeps score of his performance with ritual consistency.)Naturally, you might want to replicate such profitable results, but to do that, the answer isn't simply to copy his stock buys -- it's to emulate his investing style.