[Updated February 7, 2014]

Satya Nadella is Microsoft's new CEO. Check. He's the right person for the job, insider, change agent, provocateur. To see his 10-point todo list, see this Forrester report.

Bill Gates is leaving Microsoft's board to "substantially increase time" spent at Microsoft. Check. What, huh? How can both things be true? How can Bill Gates leave the board, but remain involved in the company?

Here's what I think will happen: Bill Gates will play a critical though invisible role in Microsoft's future. By leaving the board of directors, he won't be making strategic decisions as chairman. He won't be driving the strategic decisions as chairman of the board, but he will be a vital force behind the scenes. Here are three jobs that Mr. Gates must get right:

  1. Be silent on the strategy, transition, and plans. I believe that Mr. Gates new role is to advise and support Mr. Nadella as the new CEO pushes the company faster on a pivot to the cloud. The company has much to do. 1) Mash the products together into SaaS offerings. (Mr. Nadella has already done this with Azure, but now must do with Office 365, Skype, Dynamics, Bing, and much much more.) 2) Create a more comprehensive private cloud offering (beyond Office 365 Dedicated). 3) Break the lock between Windows and the rest of the business. (It's the only way subscription services are interesting to today's consumers and businesses. For example, Office must run everywhere.) Mr. Nadella will need help, not interference.
  2. Be an effective coach and mentor to Mr. Nadella. Bill Gates's legacy depends on helping Microsoft convert (and grow) its massive software license business to more balanced portfolio of licenses, subscriptions, devices, and new (people-delivered) services. That artful arbitrage will take a huge transformation of the product, sales, partnership, and customer strategies (and a fair amount of inorganic growth). With Mr. Nadella helm, Microsoft should be able to do it. But he will need Bill Gates's help and support starting with his quiet confidence in Nadella's tough decisions so Microsoft's 100,000 employees sign up for the transition.
  3. Remain present and be fulfilled in the Gates Foundation. Bill is half of one of the best philanthropic teams of all time. He and Melinda Gates are changing the face of philanthropy and tackling human issues that governments seem to leave unresolved. This is the place for Mr. Gates to find public fulfillment. The world needs all the help that only a foundation can energize. He and Melinda need to keep up that good work.

If Bill Gates doesn't play this run silent, run deep role, then all bets are off. If he and Mr. Ballmer are visible, even if their intentions are well meaning, the new CEO would be undermined, second-guessed, and passively blocked from accomplishing the critical business model pivot that lies ahead.