Initial teacher licensing is intended to provide public assurance of core competence in classroom settings. Core competence's implicit vulnerability is mediocrity. In daily practice, many educators appear satisfied in reaching a merely acceptable level of performance, thus minimizing the period of effortful skill acquisition required to attain core excellence. To transition from core competence to core excellence in instructional settings requires deep learning. Five professional practices reside at the heart of deep learning: a mind-set for continuous learning, an entrenched openness to feedback, deliberate practice, rigorous self-critique of instructional practices, and consistent coaching. Who is your coach?