Leagues are certainly important. We have them at Freezer's Monday through Thursday. It is one piece of the puzzle though. There are other things you need to have to be successful. Parties and events, UFC and sporting events, Sunday football, dart leagues, and so on. We would never do leagues on Friday and Saturday as we simply were too busy. Same for tournaments, small ones early would be okay but you don't want them running into your weekend nights. I would try to have them on a slower Sunday. Pool players would not even come on those weekend nights because we would have a waiting list on those nights with recreational players filling nearly 30 tables. Definitely have leagues and tournaments on your slower nights. Maybe a poker night which is legal most places if you don't take any monies and people play tournament style with chips, check your local laws of course.