"They left me in the dust as well, " Mr. Buffett wrote.

WSJ: Buffett Aides Score Big Payday

"We hit the jackpot with these two, " Mr. Buffett wrote.

WSJ: Buffett: $24 Billion Gain 'Subpar'

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).

WSJ: And Warren Buffett's Successor Is...

As the authors admit, Mr Buffett recognised these principles, and started applying them, half a century before they wrote their paper.

ECONOMIST: Beating the market with beta