In the game of basketball, does the ball just have to go through the hoop for the basket to count or does it have to pass through the net as well? I know this is an extreme rarity, but what happened if a player shoots the ball and it goes through the hoop but breaks off the side of the net and doesn't go all the way through?
Rule 5, Section I-a of the NBA Official Rule Book states that,
A legal field goal or free throw attempt shall be scored when a live ball from the playing area enters the basket from above and remains in or passes through the net.
The ball just has to pass the hoop and not necessaily through the net. If the ball gets stuck in the net or breaks off the side of the net after the ball has passed the hoop from above, it still is considered a basket.
The net is in place to slow down the ball after a basket has been made, so that there is no need to chase after it. Also it helps in making sure that a basket has been made as the ball slows down, thereby eliminating doubts when seen from certain angles.
It only has to pass through the hoop. The net is simply a device to help control the ball after it goes through the net and maybe provide a visual indicator that it made it through.