In what may come as a surprise to many, principals have remarkably little control over who teaches in their schools. For the most part, the human resources (HR) department in a district's central office, not individual school principals, makes the final call about when to hire teachers, whom to hire and in which schools they are placed. Districts generally downplay the authority of their HR offices, insisting that principals play an integral role in staffing. Such assertions are only partly true. Aside from a few notable exceptions, most districts sharply limit the authority of principals to staff their schools. So who, exactly, hires teachers? Almost all districts routinely give principals an opportunity to interview teachers for vacancies. Many also allow principals to independently advertise for, recruit and recommend good candidates for hire. "If" the district determines that a school vacancy is legitimate, "if" it has not already hired a full slate of new teachers and "if" it does not need to fill a vacancy with a teacher who was "excessed" from another school, then the principal may select the teacher. The problem with this system is that principal authority depends on too many "ifs." Even plans for reauthorizing the Elementary and Secondary Education Act, or ESEA (more recently known as NCLB), would likely give HR departments yet another reason to intervene in hiring and transfer decisions. In the goal of achieving "comparability," or ensuring that high-quality teachers are spread throughout a district, the new ESEA would tie funding to districts on the basis of whether teachers are equitably distributed throughout the district. This paper explores the problems, including this latest, that get in the way of the "ifs" and what districts and state legislatures can do differently to provide greater principal autonomy over school staffing. It explores the staffing policies in 101 school districts and points to promising practices and solutions for states and districts to consider. (Contains 8 figures.)