This study examined practices of teachers in Wake County Public Schools' (WCPSS) middle school Algebra I classes. Regression analyses of standardized state testing results allowed for identification of the most effective and least effective Algebra I teachers. The study used surveys, observations, and focus group interviews to compare and contrast most effective teachers with less effective teachers. It found that the most effective middle school algebra teachers held a significantly more positive attitude toward their students than did less effective teachers. They had high expectations for "all" students, used mathematics vocabulary appropriately, had a structured classroom management style, taught bell to bell using an invigorated pace, and had a classroom culture in which students were free to ask questions, contribute, and offer explanations. These results can be used to motivate teacher and school improvement efforts. The following appendices are included: (1) Educational Preparation and Teaching Experience: Middle School Teachers; (2) Median Ranking of Algebra Topics; (3) Rankings of Algebra Topics; (4) Percentage of Instructional Time by Delivery Method; (5) Teacher Attitude Responses; and (6) P-Values.