My colleague Johannes recently mentioned the so called "70-20-10" rule in passing. Here is a quick breakdown.

It was initially developed to guide how people learn and grow at work.1 The researchers surveyed nearly 200 successful executives, asking them to identify the key events in their careers that made them more effective leaders. Based on the responses, they distilled the learning process into three categories:

Percentage Type of Learning Description
70% Challenging Assignments "On-the-job" experience, solving problems, and handling new responsibilities.
20% Developmental Relationships Learning through others (mentors, bosses, feedback, and observation).
10% Coursework & Training Formal education, seminars, and reading.

In the early 2000s, Eric Schmidt2 adapted the learning ratio into a strategic framework to ensure Google didn't lose its innovative edge while scaling its massive search business.

Percentage Type of Work Description Examples
70% Core Business To sustain and improve the primary revenue drivers. Search, AdWords, Infrastructure.
20% Adjacent Emerging Stars To scale products that have shown promise but aren't yet "core." Google Drive, Maps, Gmail (in their early years).
10% Radical Innovative Moonshots To explore high-risk, high-reward ideas for the distant future. Waymo (Self-driving), Project Loon, AlphaGo.

  1. 1

    The CAREER ARCHITECT® Development Planner by Morgan McCall, Michael M. Lombardo and Robert A. Eichinger

  2. 2

    How Google Works by Eric Schmidt and Jonathan Rosenberg