Money Player.

Would you take stock tips from a man who once said he avoided books because reading might impair his batting eye? TheStreet.com thinks you should. Last month the financial news website began publishing Nails on the Numbers, a weekly column by former Mets and Phillies centerfielder Lenny Dykstra. The ex-leadoff man, 42, offers stock leads ranked from home runs to singles. Says the man who also once wondered aloud if London was a country, "The home run picks are the ones that really matter. So far mine all went to Pluto--all north, bro."

Dykstra, who owns three car washes in Southern California, used to let others handle his investments, but he got serious about the market after losing a half-million dollars in the dot-com collapse. He began devouring Wall Street newsletters and, helped by the market's resurgence in 2003, he recouped his losses. "I was surprised he picked it up so quickly," says Richard Suttmeier, Dykstra's mentor and a chief market strategist for an investment-banking firm.

Dykstra appeared in June on a radio show with Suttmeier, who writes the technology report for TheStreet.com. "Lenny said to me, 'You know, dude, I could write a column for you guys, too.'" Site cofounder Jim Cramer, the kinetic host of CNBC's Mad Money, went for it, and Dykstra's gig also includes a weekly appearance on Cramer's radio show.

Dykstra's strategy is to buy undervalued stocks and sell when they reach a preordained profit margin. "The buy-and-hold days are done," he says. His TheStreet.com column is popular, but rival touts are skeptical of his insights. "It's the kind of advice thousands of brokers would provide," says Bill Power of The Wall Street Journal.

Such scoffing doesn't bother someone known as Nails. "It's good when your opponent hates you," says Dykstra. "That's how it was when I played, but my teammates loved me."