What would happen if people found agreement around the world on what constitutes high-expertise teaching? For one thing, there would be a set of standards universally embraced that clearly defines core agreements about good teaching and learning. It would be obvious that proficiency in the knowledge, skills, and practices that comprise good teaching would be the highest-leverage path to increasing student achievement. Teacher preparation and subsequent professional development for all teachers everywhere would be based on the standards. Every effort would be made to assure that expert practices show up consistently in every classroom--from widely available classroom coaching on these practices to policies that reflect public will to focus on expertise. That scenario is not a distant fantasy; it is fast approaching if one looks around the globe. In this article, the author contends that all teachers must be supported and enabled to experience professional development in the building blocks of successful teaching and learning.