Alman's right...
Over the years, alot of people have really been burned by blindly following the numbers. LTCM is a major example.
Although statistics, used in the right way can be a great tool.
For example, George Soros. Founder of Soros Funds Management, former manager of his Quantum Fund, the best performing fund in history. 30% annual returns for 20 years (or something close to that). He's currently worth $7 Billion (USD).
Soros uses common sense in relation to his bets on financial products. He times alot of his trades through statistics.
I think when it comes down to it. Common sense and forward thinking (as well as a few accurate calculations) makes for good stock investment.
For speculative trading, statistics can make give someone a huge edge.
GM
Edit: FYI, when i say statistics, i mean "the numbers" in general...