Bill Gates and Warren Buffett have been friends for almost 30 years. The two geniuses clearly enjoy learning from one another. This week, Gates adopted one of Buffett's favorite communication tactics and gave his friend the credit.

The tactic Gates adopted from Buffett is metaphor, a literary device through which we describe one thing in terms of another. It's an ancient figure of speech that Aristotle recommended some 2,000 years ago. Today every educator, entrepreneur and business professional should include it in their verbal toolkit.

Bill Gates "Swings for the Fences"

On Monday, Bill and Melinda Gates released their annual Gates Foundation letter titled, Why we swing for the fences. The 7,000-word letter highlights the accomplishments of the Gates Foundation over the past twenty years and the lessons they've learned after spending $53 billion to solve some of the world's biggest health and education challenges. 

In the letter, Bill Gates explains how Buffett inspired this year's theme and title. When Buffett donated much of his fortune to the Gates Foundation in 2006, he urged the couple to "swing for the fences."

"That's a phrase many Americans will recognize from baseball," Gates writes. "When you swing for the fences, you're putting every ounce of strength into hitting the ball as far as possible. You know that your bat might miss the ball entirely--but that if you succeed in making contact, the rewards can be huge."

Gates then applied the metaphor to the goals of the foundation. "That's how we think about our philanthropy, too," he wrote. "The goal isn't just incremental progress. It's to put the full force of our efforts and resources behind the big bets that, if successful, will save and improve lives."

Bill and Melinda say their big bets have saved millions of lives. They'll now apply the same metaphor and its lessons to finding solutions to other big problems like climate change.

On a written note in the margins of the letter, Bill wrote: "You know Warren was on to something when he's got me using a sports metaphor."

Sports metaphors are among Buffett's favorite comparisons to explain financial concepts.

Warren Buffett, a Master of Metaphor

In my most recent book, Five Stars, I devote an entire chapter to metaphor, a rhetorical technique that Aristotle said gives language its 'verbal beauty.' I could find no better business practitioner of the art than Warren Buffett.

In an HBO documentary on Buffett, the billionaire is asked to articulate his investment philosophy. Buffett cites a book by baseball legend Ted Williams called The Science of Hitting. In it, Williams divided the strike zone into squares.

"If he waited for the pitch that was really in his sweet spot, he would bat .400," Buffett explained. "If he had to swing at something on the lower corner, he would probably bat .235. The trick in investing is to watch pitch after pitch go by and wait for the one right in your sweet spot."

Buffett is also fond of using medieval analogies. He looks for companies that are like "economic castles," surrounded by a strong moat that makes it difficult for invaders--competitors--to gain a foothold in the market.

A Simple Way to Communicate a Novel Idea

Metaphor and its close cousin--analogy--are fundamental devices that persuasive speakers use to make people comfortable with unfamiliar or complex topics. It makes the abstract, tangible. 

Founders and entrepreneurs should incorporate metaphor into their pitches, presentations and sales strategies. The simplest way is to compare a novel idea or new product to something concrete that the audience knows. 

For example, when I advised Intel years ago on a communication strategy for its first 'dual-core' computer chip, we compared the microprocessor to the "brains" of a computer. Dual-core chips were like getting two brains in one system. While one brain worked on one task, the other worked on another, making the system faster and better in every way. 

Once you and your team decide which analogies or metaphors are the most apropriate, use them in every conversation, presentation or sales meeting on the topic. Since the human brain is wired to find something tangible to make sense of abstractions, your listeners will instantly pay more attention.