As a retired college prof for 30 years, I was very involved in the training of teachers. School rankings are often another dog and pony show. Most teachers are very dedicated and try to do their best. Some are more capable than others for sure, but it is extremely difficult to grade them as there are so many opinions about who and what is a good teacher. Most are underpaid and have to jump through multiple hoops not only to get certification but to justify their job as well while teaching. Policemen have to endure the same oversight by those who have never been one. They get tired of criticism and need encouragement and an occasional "atta boy".

Schools should be graded by the parental involvement in the district. I imagine most of the schools that got high grades have an active parent pool. Without question, this is the overall deciding factor in the success of the student and school. It's not about money and social class. It's about parental support and involvement with their kids.