Mark Pincus has stepped down from all operational roles at Zynga, the San Francisco-based social gaming company he founded in 2007.

In a memo to employees today, Pincus wrote:

“I’m writing today to share that I have decided to change my role to non-executive Chairman. This means that, while I’ll still keep an office at Zynga, and be active in supporting the company, I will not have an operating role. Most importantly, I remain Zynga’s largest shareholder and biggest believer.”

He also did an interview with me earlier today, noting that it was time for one “captain” — in this case, CEO Don Mattrick, who replaced him as top leader last year — to be helping the troubled boat come back from big declines in usage and layoffs. The move came after 10 months of transition, said Pincus, after talking it over with Mattrick.

“I feel like a fisherman and when the fish are running, it has been exhilarating, and when they are not running you are restless,” said Pincus. “He asked me if what I was doing was something I would be passionate doing for the next three or four years and satisfy the level of energy I had.”

The answer was no.

Looking back at his rocky tenure at Zynga — the company went from obscurity to phenom to hangdog rather quickly — he said that he would give himself a mixed grade.

“I think I give myself high marks being an entrepreneur and entrepreneuring a big idea about how popular social gaming could be,” said Pincus. “But I learned a lot of hard lessons on the CEO front … and do not give myself very high marks as a CEO of a large-scale company.”

Among those mistakes was growing Zynga too quickly to 4,000 employees in just four years. “I think it is rewarding to manage, but it is not what I am passionate about,” he said. “Managing more than 200 people, maybe 150 people, isn’t fun to me and is not my skill set.”

One of his lessons has been separating good instincts from bad ideas, as well as making sure he remained more flexible to change. “It’s important to take a lot of shots on goal, which I think we did at Zynga,” he said.

But looking at some of the more difficult times, he said that he looks at Zynga as a professional sports team. “You are as good as your product,” Pincus said. “When you are used and loved by everyone, your brand equity is high. When you are not, you’re not.”

Still, he correctly noted that Zynga was one of the first app-focused companies and one of the early users of immense amounts of data to determine what users wanted.

And though leaving his day-to-day duties, Pincus noted that he was not departing completely. “I am going to be working on exploring other things and not going to be part of the management team,” he said. “But I will always think of Zynga as a part of me.”

Here is the full text of the memo that Pincus sent to employees:

Team Zynga,

I’m writing today to share that I have decided to change my role to non-executive Chairman. This means that, while I’ll still keep an office at Zynga, and be active in supporting the company, I will not have an operating role. Most importantly, I remain Zynga’s largest shareholder and biggest believer.

I have full faith in Don’s leadership and ability to take Zynga to its next level. Over the past 10 months it has been great to work with Don and you all to reshape our company for the future. While that effort is still in early stages, we can already see exciting milestones like Zynga Poker returning to growth, Farmville 2’s recent mobile launch (hitting #1 free US iPad app this week) and the addition of the talent, technology and IP from Natural Motion.

This progress you have all made is remarkable, and it is just a hint of things to come. Together, we have reached more than 1 billion people through our games and enabled them to make valuable and even life changing connections. The most gratifying part is receiving emails such as the one I got this past weekend from a player named Justin Burkett from Escondido, California who met the love of his life playing Words With Friends.

Zynga today represents a unique combination of assets, talent and opportunity. No other company offers consumers our breadth of game offerings and dedication to combining consumer accessibility with fun and social.

I’m confident that Don, along with our amazing creative and technical product leaders will continue to focus on innovating in social gaming, driving mobile growth and building out our strong franchises — FarmVille, Words With Friends and Zynga Poker, as well as inventing new brands that will delight and connect more players. Their leadership skills combined with your passion and inspired work will take Zynga to our next chapter of growth, as we pursue our mission of connecting the world through games.

I want to thank you all for the amazing contributions you have made so far, not just to Zynga, but to tens of millions of people around the world who, because of you, have decided to make play a key part of their day.

Please continue to feel free to reach out to me. I will always respond to your emails and passionately partner with you on new ideas for your products.

Here’s to killing it in 2014!

Mark