how much of the puck has to cross the line
Goal (ice hockey) For a goal to be scored, the puck must entirely cross the goal line between the posts and under the crossbar of the goal frame. A goal is not allowed under any of the following conditions:
Field goal The goal structure consists of a horizontal crossbar suspended 10 feet (3.0 m) above the ground, with two vertical goalposts 18 feet 6 inches (5.64 m) apart extending vertically from each end of the crossbar.[1] In American football the goals are centered on each end line; in Canadian football the goals are centered on each goal line.