Single vs. Multiple DBs || Which way to go?

Hey all. I'm attempting to organize a sport report site into working order. We've got approximately 100 tables, and I'm unsure whether to break the info up by sport (i.e. baseball, basketball, hockey, etc.) or to lump all the tables in one db and prefix tables by their sport name (e.g. bk_scoring = basketball scoring table). On the surface, it would seem easier to use multiple dbs, but then again, common tables, such as schools and coach_info would have to be duplicated in each db. Any ideas/suggestions much appreciated, --Noah --