The time to weed out ineffective teachers is in their training year, during teaching practice.
I remember one dreadful example whom I and my department did our best to support, going to the lengths of allowing her to try out her assessment lesson on a parallel class beforehand.
I finally realised that we were in grave danger of pushing an incompetent into the classroom and told her examiner some of the history. His comment was that, but for what I had told him, he would have passed her with flying colours.
Rachel Gibbons, Retired inspector, founder of SMILE Action Group.