This is for dude's lacrosse of course and I'll keep it short. Okay, out of bounds: It's mostly who is closest. Unless there was a penalty. That's why the race to the sidelines. Lengths of the sticks. Attackman, middies and some D use the shorter (30" usually) handle. Defense are the poles (up to 72"). Depending on the age group, field and a few other things determines how many long stickman play but it's usually two. The D-pole guys will and do beat the holy shit of your hands and arms. The face off guys have become such a specialty that most college and all pro teams will have a FOGO. Face off get off. It's a lot hard than it looks. lol! They will have a back up because they get gassed or injured. Womens has less checking but it's still pretty aggressive.