“But if your overall approach is right, you can improve the probabilities of success,” he says, “and I think that’s what we’ve done.”

His particular approach relies on skills that he says are “practically extinct.” They were honed as an auditor with the old Arthur Andersen & Company, and then, in the 1970s, as co-author of The Quality of Earnings, a financial newsletter that shed light on the murky areas of corporate accounting.

While he is aware of macroeconomic trends, he takes a bottom-up approach that isn’t very fashionable these days.

“On Wall Street, so many people are basically just momentum investors, looking for growth and following whatever is trending up,” he says. “The market is becoming a casino. I don’t play that game. I care about specific companies and whether they are good buys at their price, and if they are, we’ll hold on to them.”

Mr. Olstein looks for stocks that are underappreciated, and that are strong in a metric he has always favored: “free cash flow yield.” (It is cash, after subtracting capital expenditures and working capital, divided by market capitalization.) “Cash is king,” he says. “That’s what you’re paying for when you buy a stock — the ability to generate cash. But few people even bother with it these days.”

He says he prefers “boring companies” — if their free cash flow excites him. One such company is John Deere, the agricultural equipment maker. He estimates that its free cash flow yield is about 7 percent, a very high level, and that it’s likely to grow to 10 percent over the next three years. Its recent prices have been depressed by temporary phenomena like poor weather and low corn prices, which have slowed down worldwide equipment purchases. Over the long haul, though, with global population swelling and demand for food increasing, he says, the odds are good that Deere will rise in price.

He contrasts Deere with Cisco Systems, the Internet hardware company. Deere has been boring for decades, he says, while Cisco was one of the most exciting in the stock market in the late 1990s. Back then, he took a bearish view on Cisco — correctly, as it turned out.