Studies link principal effectiveness to lower average rates of teacher turnover. However, principals need not target retention efforts equally to all teachers. Instead, strong principals may seek to strategically influence the composition of their school's teaching force by retaining high performers and not retaining lower performers. We investigate such strategic retention behaviors with longitudinal data from Tennessee. Using multiple measures of teacher and principal effectiveness, we document that indeed more effective principals see lower rates of teacher turnover, on average. Moreover, this lower turnover is concentrated among high-performing teachers. In contrast, turnover rates of the lowest-performing teachers, as measured by classroom observation scores, increase substantially under higher-rated principals. This pattern is more apparent in advantaged schools and schools with stable leadership.