The reality is that even at good school systems, there are varying levels of teacher ability, and often drastic levels of teacher motivation. If a school could guarentee a competent, motivated teacher every year for my kids, I wouldn't have ever considered homeschooling. But that, quite frankly, is never the case. I have 3 kids in public school and one in private. Two have great teachers, but one had a weak teacher last year. My older kids change classes, and of their 4 teachers, we have one great, one good, one average, and one outright bad. And this is one of the best schools in the best school system in the state.