The Economist tidily sums up billg's career this week, now that Microsoft's Rain Man (see video) has walked away from the company after 33 years. I've whittled the piece down to its talking points.

When Bill Gates helped to found Microsoft there was a company rule that no employees should work for a boss who wrote worse computer code than they did. Just five years later, Mr Gates hired a business manager, Steve Ballmer, who had cut his teeth at Procter & Gamble, which sells soap.

In becoming the world’s richest man, Mr Gates’s unswerving self-belief has repeatedly been punctuated by that sort of pragmatism. To let it all go is to acknowledge that his best work at Microsoft is behind him. It is to accept that the innovator’s curse is to be transitory.

Mr Gates’s vision has come to seem so obvious that it is hard to imagine the world any other way. Yet, early on, he grasped two things that were far from obvious at the time:

  • Computing could be a high-volume, low-margin business. Until Microsoft came along, the big money was in maintaining a select family of very grand mainframes. Profit would come from selling a lot of them cheaply, not servicing a few at a great price.
  • Making hardware and writing software could be stronger as separate businesses. When mighty IBM unwittingly granted Microsoft the right to sell its PC operating system to other hardware firms, it did not see that it was creating legions of rivals for itself. Gates did.

Mr Gates’s invention was as a businessman. His genius was to understand what he needed and work out how to obtain it, however long it took. In an industry in which visionaries are often sniffy about anyone else’s ideas, the readiness to go elsewhere proved a devastating advantage.

Gates had the good fortune to be perfectly suited for his time—but he is less well-equipped for the collaborative and fragmented era of Internet computing. Some great industrialists, like Henry Ford, stick around even as the world moves on and their powers fail. Mr Gates, pragmatic to the end, is leaving at the top.