Seems like 3:
“For example, hiring rules give high-poverty schools fewer teachers to choose from than wealthier schools. The rules also lead to staffing of these underperforming schools with more difficult-to-place teachers and can cause the schools to lose their newly trained teachers after just two years.
“A longtime principal at a high-poverty school told us that high-poverty schools “not only get the least-qualified new applicants, but then we get the people who are guaranteed jobs but have been passed over for openings at other schools.”
Thomas Sowell pointed out that the worst teachers end up at the worst schools. In large cities, those are generally black schools.
Fifteen to twenty years ago, I spent a lot of time, as a freelance photographer with a private company, going into Chicago Public Schools to take candid photos in classrooms and to photograph school events.
In the black schools, almost all the teachers are black. The ataff is black. The Administration is black. Most of the students don't even show up for school. Promotions to the next grade are based on age, and so are the awarding of diplomas.
Draw your own conclusions.