How do teachers talk about the productiveness of teacher's in-the-moment responses to student mathematical thinking? This is a question current research does not fully answer as most research on teacher moves is focused on what teacher moves researchers have noticed teachers do rather than on what teachers think about these teacher moves. To fill the gap in the research and to answer the question, a group of 13 teachers were given ten classroom situations to compare and contrast for productivity. I analyzed (a) the content of the teachers' discussions by drawing on Teacher Response Coding (TRC) language, and (b) the extent to which the teachers' discussions align with theorized productive responses to student mathematical thinking, or building. From the teachers' group conversations, I articulated principles of productivity— articulations of the main ideas and conclusions of the teachers' conversations with regards to productivity. Focusing on the principles of productivity, I highlighted what teacher moves the teachers said were productive or not productive with respect to teacher's in-the-moment responses to student mathematical thinking. In analyzing the list of unique principles of productivity, I noticed three main themes that the principles were focused around: student mathematics, teacher moves, and mathematics, which reflected some of the ideas in research for productive teacher moves. Additionally, I analyzed the principles for alignment with the practice of building, which led to the conclusion that the ideas of orchestrating discussion and making explicit are the most salient of the sub-practices of building to the teachers. These results based on teachers' discussions around the productivity of teacher moves can help inform teacher education and professional development.