Elon Musk arm-wrestled his business partner to settle PayPal software dispute: book

• Max Levchin told Elon Musk's biographer about the difficulties of working with the maverick billionaire.
• In the early days of PayPal, Musk suggested an arm-wrestle to resolve an argument over software.

Elon Musk challenged his PayPal business partner, Max Levchin, to an arm-wrestle to settle a software argument, according to a new biography.

In 2000, Musk's X.com, an online bank, had merged with Confinity, a competitor co-founded by like-minded Silicon Valley entrepreneurs Peter Thiel and Levchin. The early days of the company, soon to become PayPal, were filled with clashes over everything from its name to which operating system they should run on, per Walter Isaacson's book.

Levchin, described by Isaacson as "a low-key and super-sharp Ukrainian-born software wizard," worked in close partnership with Musk, but the two disagreed on which operating system X.com should use.

Musk thought Microsoft would be more reliable, whereas Levchin saw it as "insecure, buggy, and uncool", preferring Unix.

"Eventually you will see it my way," an unwavering Musk told Levchin, according to the biography. "I know how this movie ends."

But rather than a discussion about the pros and cons, Musk told Levchin late one evening: "You know what – I will arm-wrestle you for it."

Levchin told Isaacson he though this was "the stupidest imaginable way to settle a software-coding disagreement." But claiming that "he was loopy from working late hours" and forgetting Musk was almost twice his size, he agreed to the arm-wrestle.

Levchin lost, but warned Musk: "I'm not going to use your physical weight as any sort of a technical decision input."

Musk took no heed. Isaacson writes that Musk had his own team of engineers rewrite the Levchin's Unix code for Confinity, while neglecting the growing amount of fraud plaguing X.com.

"The only reason we remained successful was because there were no other companies being funded during that time," Levchin claims in the biography.

Yet Levchin also saw nuance in Musk's character. "There's an irony in everything he does," he told Isaacson. "He operates on an irony setting that goes up to eleven, but never goes below four."

Similarly, Levchin recounts moments of Musk's brilliance, like when he immediately solved a technical problem with an Oracle database that Levchin and his team had been wrestling with.

"Elon will say crazy stuff, but every once in a while, he'll surprise you by knowing way more than you do about your own speciality," Levchin told Isaacson.

In 2001 X.com was renamed PayPal, and Thiel and Levchin went on to oust Musk as CEO, pushing him on to other ventures.

Some 16 years later Musk acquired the domain name X.com from PayPal, tweeting that it had "great sentimental value to me." He went on to rebrand Twitter as X.com in July.