As the two-year anniversary of Alphabet’s corporate restructuring approaches, Page wrote in a letter to investors that the model has empowered entrepreneurs outside its core search business.

“The new structure has helped entrepreneurs build and run companies with the autonomy and speed they need,” he wrote in the letter published ahead of the Mountain View, Calif.-based company’s earnings on Thursday.

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Page took Silicon Valley by surprise in August 2015 with the creation of a new company, Alphabet, to house Google and new ventures ranging from self-driving cars to health technology, which would be broken off into separate companies. The structure was intended to give investors greater visibility into the search unit’s performance and give leaders of the new businesses more autonomy.

Wall Street has cheered the new structure, but it has had mixed results. The self-driving car group has graduated into a new company, dubbed Waymo, but a host of Alphabet executives have departed, including the leaders of smart home technology company Nest and Google Ventures.

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Since the restructuring, executives have learned a great deal about how to best launch the new companies, Page wrote, citing the spin-off of Waymo in December.

“In general we are taking a patient approach to investing our capital,” he said. “We’re not going to invest if we don’t see great opportunities and we feel like our track record for picking some important efforts long before others is pretty good.”