Michelle is a first-year English teacher at Vailsburg Middle School, a public school in Newark, New Jersey. Michelle is dedicated, caring, energetic, and insightful. This year, the author had the chance to watch Michelle and her principal, Serena Savarirayan, meet for their weekly debriefing of Michelle's teaching. Serena began by praising Michelle's progress toward the goal they'd set at the last meeting--adding more wait time after asking challenging vocabulary questions. As she spoke, Serena updated the "Progress Toward Goals" section of the spreadsheet she uses to track her observations, noting that Michelle was progressing toward this target. The focus then shifted. During her most recent 15-minute visit to Michelle's class, Serena had noticed that when Michelle solicited a whole-class choral response for a grammar question, several students did not participate. To address this, the pair identified specific responses Michelle could have made in the situation. Then Michelle and Serena did something different. Serena pretended to be a recalcitrant student and Michelle practiced moving closer and giving a quick nonverbal correction to bring Serena into the class chant. Finally, the two recorded "full participation in choral response" as the next key goal and planned to follow up later in the week. For Serena, the core driver of teacher development is not accurate scoring, but skillful coaching, working with instructors on specific concrete actions that will improve results. This article examines three ways leaders like Serena practice this coaching model: (1) Conduct more frequent observations; (2) Practice, practice, practice; and (3) Coach for growth--not for scores. Coaching makes teachers great. When teachers see the concrete steps they must take to improve their practice, and when they can continually practice skills connected to those steps, transformational success comes within reach. (Contains 1 figure.)