"Who can fill Warren Buffett's shoes? "

The chairman and chief executive of Berkshire Hathaway, who has run the conglomerate since 1965, announced this week that he has prostate cancer. The disease was detected early, and the 81-year-old Mr. Buffett is otherwise in excellent health. His prognosis is good.

WSJ's Jason Zweig visits Mean Street to handicap the succession plan at Berkshire Hathaway to fill Warren Buffett's shoes. Photo: AP.

But the news brought renewed attention to the question of who ultimately will succeed him. A skilled bridge player, Mr. Buffett is keeping his cards close to his vest. He has said the members of Berkshire's board have chosen a successor whom they know and admire, as well as two backups.

Yet he hasn't disclosed the successor's identity—even to the chosen person. Nor would he reveal anything during my brief conversation with him this past week.

From the Mouth of Warren Buffett

See how often Mr. Buffett has mentioned current division bosses in annual shareholder letters, plus see analysis from two research groups on how positively he speaks of each, and read highlights.

Just the Documents, Please

Explore the Berkshire Hathaway annual shareholder letters, from 1977-2011.

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Publicly naming his successor wouldn't just make it hard for Berkshire to change its mind later if circumstances warrant; it would demoralize the two backup choices and make them more prone to poaching by competitors.

The successor will "probably be somebody who surprises us," says David Winters, a shareholder for more than two decades whose mutual fund, the Wintergreen Fund, holds $67 million in Berkshire stock. "I would bet on somebody who doesn't have a high profile and who is not in the rumor mill."

In hopes of unearthing some of those surprising names, I asked two independent teams of financial researchers—Paul Tetlock and Tim Scully at Columbia Business School and Richard Peterson at Los Angeles-based investment firm MarketPsych—to analyze what Mr. Buffett has written about Berkshire's divisional executives in his annual letters.

Both groups of researchers specialize in "textual analysis," or the use of mathematical formulas to measure the frequency and positive or negative tone of language. In previous studies—for example, of the wording in companies' financial filings—these methods have been shown to improve forecasts of profitability.

Since 1977, Mr. Buffett has written nearly 400,000 words in his annual letters to shareholders. Messrs. Tetlock and Scully found that Mr. Buffett has mentioned Ajit Jain, head of Berkshire's reinsurance group, far more often than any other current division boss—102 times, versus 60 for the next most-cited, Tony Nicely of Geico.

They found that Mr. Buffett referred slightly more positively to Mr. Jain than he did to any other Berkshire manager. However, Tad Montross, CEO of General Re, scored a close second for overall positivity and nudged out Mr. Jain in the proportion of financially positive words Mr. Buffett used. (For example, in his 2002 letter, Mr. Buffett wrote of "enormous progress" under Mr. Montross.) Not far behind were CEOs Brad Kinstler, of See's candy; Greg Abel, of MidAmerican Energy; Don Wurster, of National Indemnity; Mr. Nicely; and Kevin Clayton, of Clayton Homes.

Christophe Vorlet for The Wall Street Journal

Using a different methodology that scores words by their association with happiness, Mr. Peterson found that Mr. Jain ranked considerably lower.

Among the current executives to whom Mr. Buffett has referred in emotional terms at least eight times, the one who scored the highest is Danny Goldman, chief financial officer of Iscar, Berkshire's Israeli-based cutting-tool division ("incredible," wrote Mr. Buffett in his 2009 letter, for example).

Mr. Nicely of Geico comes next ("stellar," as the 2005 letter put it), followed by Mr. Abel of MidAmerican ("terrific," 2008), Mr. Kinstler of See's ("extraordinary," 2007), Tom Nerney of U.S. Liability Insurance ("fabulous," 2002) and Mr. Jain ("amazing," 2006).

Among divisional CEOs to whom Mr. Buffett has referred at least four times in emotional terms, Mr. Peterson gives high positivity scores to Paul Andrews, of electronics distributor TTI; Jacob Harpaz, of Iscar; Grady Rosier of supply-chain manager McLane; and Matt Rose, of Burlington Northern Santa Fe railroad.

By far, the person to whom Mr. Buffett has referred the most is Ajit Jain. "This is true whether you look at the number of references, number of words or simply the number of years that he's mentioned," says Mr. Tetlock. Nevertheless, he warns, any inferences based, as these are, on a relatively small number of references "should be taken with far more than a grain of salt."

To be sure, being praised isn't the same as being crowned. Several executives Mr. Buffett has lauded lavishly in the past—including David Sokol, Joe Brandon and Rich Santulli—are no longer at Berkshire.

Still, textual analysis "is better than a plain guess, because it has some statistical underpinning to it," says Mr. Peterson. "The probability should at least be higher than experts' random estimates."

Berkshire's board, at least, knows who Mr. Buffett's successor will be. That is more unusual than you might think.

"Succession planning at most companies is a hollow exercise," says David Larcker, an expert on the topic who teaches at Stanford University's business school. "It's rare to have a plan in place where you know the next day [after a CEO dies] exactly what you're going to do."

"Business Lessons from the Titanic (in 3D)"

This month the blockbuster movie Titanic was re-released in 3D. With special glasses, audience-goers are now able to see the ship crash into the iceberg even more vividly than before. In true Hollywood style, the film depicts a massive iceberg looming over the "unsinkable" ship with the crew scrambling to avoid a head-on collision.

We usually think of threats in this way: something big and dangerous that can sneak up and overwhelm us when we aren't looking. But the real story of the Titanic paints a different picture. It is a story that, while less dramatic, offers relevant lessons for leaders navigating their organizations through icy waters.

You've Been Warned

The Titanic received six warnings of ice on the day of the collision. They were all ignored by the wireless operator, who was preoccupied with transmitting passenger messages and by the crew, who were focused on breaking the speed record. So pay attention. The signs are already there if you listen. Some companies, like Borders, Kodak and Polaroid, ignore the signs. Others, like Domino's Pizza, catch themselves before it is too late.

Size Doesn't Matter

The iceberg that the Titanic struck was not very big. It didn't even come up as high as the bridge of the ship. And the hole in the boat was actually quite small — six cuts measuring a little over three square feet.

Our brains are wired to think of threats as coming from something bigger, but it's often the little things that become our downfall. Clay Christensen's work on disruptive innovation shows the power of David against Goliath, the mammal over the dinosaur, the startup over the incumbent.

It's What You Can't See

The iceberg that struck the Titanic was almost invisible. Continuous melting had given it a clear, mirror-like surface which reflected the water and dark night sky, like black ice on a wintry road. This type of iceberg is called a "blackberg." It is possible that the crew could have been looking right at the iceberg from a distance and not seen anything unusual.

Look Below the Surface

Only about ten percent of an iceberg's mass is above water, with the other ninety percent below (hence the phrase "tip of the iceberg.") With so much mass below the surface, it's almost impossible to push an iceberg out of the way. Even a ship the size of the Titanic couldn't push what looked like a small iceberg out of the way.

Keep Moving

When First Officer Murdoch saw the iceberg, he put the engines in reverse and started turning away from the iceberg. It's a natural reaction to hit the brakes when you see a threat. But this action may have sealed the Titanic's fate. Ships turn more quickly when they have forward motion. If the captain had maintained the ship's speed or even accelerated, he might have avoided hitting the iceberg altogether.

So as you think about your business, think what warning signs you might have overlooked. Consider where the icebergs might be that you can't see, or where the threats might look deceptively small on the surface. And when you do see a threat, beware of hitting the brakes; the best reaction might be to step on the gas.