How Hillary Clinton overcame the challenge from Sen. Bernie Sanders. Hillary Clinton greets supporters during a rally at Long Beach City College on the final day of California campaigning. Photo: Jonathan Alcorn/AFP/Getty Images.
Without the rule, offensive players could hover near their opponents' goal even when the play is on the other side of the field, with the hope of a long pass and an easy goal. The offside rule applies at the moment the ball is touched or passed, not when the ball is received.
It will appear that a lot of the team are just standing around watching things happen, but the reality of the situation is that they are unable to make a play on the ball because they are offside and must instead position themselves for play after someone else has touched the ball, thus playing them onside.