The National Council on Teacher Quality (NCTQ) has long advocated that any meaningful understanding of "effective" teaching must be rooted in results for kids. Whatever else they accomplish in the classroom, effective teachers improve student achievement. It seems like commonsense. Yet, until recently, it has been an exceptional way of thinking about teacher quality, totally out of step with teacher policy across the states. As part of the annual State Teacher Policy Yearbook, NCTQ has systematically collected and analyzed state policies on teacher preparation, training, retention, compensation and other personnel policies. In this paper we provide: 1. A detailed and up-to-date lay of the land on teacher evaluation policies across the 50 states and the District of Columbia Public Schools; 2. An in-depth look at policy in states promising ambitious teacher evaluation systems (states requiring student growth and achievement to be a significant or the most significant factor in teacher ratings), including states' efforts to "connect the dots" and use teacher evaluation results in meaningful ways to inform policy and practice; 3. A compilation of some of the important lessons learned, pitfalls and successes states have experienced on the road to improving teacher evaluation systems.