Three years ago, we opened a school with master, flex-paced, blended learning. Onboarding students and staff over three years was full of dips and small wins. This session will review our "why" for needed mastery learning on a flexible timeline, breaking Carnegie. We will share how we used MCP and the semester-by-semester evolution of our school. Six semesters in, and six different versions so far. We will close with our current "playbook" of non-negotiable resources. This session is for leaders and practitioners.