text: I think that this is a good idea but you shouldn't base it on grades, instead you should base it on citizenship marks. Like I said what if the kid is a bit slow and cant help but get bad grades then what? My idea is to use citizenship marks to define weather or not to let them join sports. If that doesn't suit you then i suggest to first check their background first before you decide any ways I still think that you should put this rule into affect after this trimester so kids can adjust.