Asked to pen an endorsement for Paul Allen’s new autobiography, Bono, a well-known musician, declares that the co-founder of Microsoft’s “…intellect and generosity of spirit are there on every page”. He is only half right. “Idea Man” does provide plenty of insights into the ways in which Mr. Allen has helped revolutionize everything from software to space travel. But its pages are also permeated by bitterness towards Bill Gates, the man with whom he created a company that transformed the world of technology. Indeed, there are enough sour grapes in these pages to fill an entire vineyard.

The irony is that the primary focus of Mr. Allen’s resentment—his co-founder’s intense competitiveness—is also one of the things that propelled Microsoft to greatness. That trait, and the tension that it provoked between the two men, is evident from the time they meet at school. Mr. Allen describes how Mr. Gates became restless when a practical joke he played on Mr. Allen backfired. In another scene, he portrays his pal sweeping the pieces off a chessboard in fury when he lost yet another game to Mr. Allen.

As any veteran of a start-up will tell you, the strains of building a company can be enough to undermine even the strongest partnerships. In the case of Microsoft, set up in 1975, the surprising thing is that the union between the two men lasted as long as it did given the tension that already underlay their friendship. Mr. Allen eventually walked out of the company in 1983, leaving Mr. Gates in sole charge of Microsoft, which then went on to turn both men into billionaires.

The main reason the tandem held together for more than a couple of years was that each of the entrepreneurs brought something valuable to the table. Mr. Gates’s single-minded focus on winning everything, whether a chess game or a vital business deal, was complemented by his partner’s ability to see the bigger picture—an ability reinforced by Mr. Allen’s diverse set of outside interests, ranging from music to sport and science fiction. Mr. Allen acknowledges that the two men were “extraordinary partners”. He likens their union to that of Bill Hewlett and David Packard, or Larry Page and Sergey Brin, the founders of Google.

But rather than going on to give Mr. Gates the considerable praise he is due for turning Microsoft into a corporate Leviathan as its chief executive, the book instead dwells on the clashes that the two men got into over the size of their respective ownership stakes while they were still working together—arguments that were fueled by Mr. Gates’s fear that his partner was not sufficiently committed to making Microsoft a success. In the end, Mr. Allen, who has already suffered two bouts of cancer, decided to leave to pursue other projects.

The story of “chessboard fury” attempts to indicate that________.