It's wonderful when a child and teacher are well-matched, but when creating classrooms, the school also considers the dynamic of the group. Although, we had a year when the teacher would have been fine, but somehow the dynamics across the entire 2nd grade were disastrous. You could tell on the first day that things weren't right. DS came home in tears a few days a week gasping "I just want to learn." Halfway through the year, they regrouped by math readiness because no one, least of all DS, was learning, and things improved. The next year, not only did he have a wonderful teacher (and start the accelerated math and LA classes) the class make-up had everyone smiling on the first day of school, and it lasted all year.
