be relative to the puck, resulting in players standing deep in their offensive zone while waiting for teammates to bring the puck forward. As a result, the NHL introduced the modern offside rule on December 16, 1929, effective six days later. The rink was divided into three zones by two blue lines as of the 1928–29 season, and the centre line did not yet exist. Teams were allowed a forward pass in any of the zones, but the puck must be carried over a blue line by a skater. Frank Boucher and Cecil Duncan introduced the centre red line in the 1943–44 season, in an effort to open up the game by reducing the number of offside infractions and create excitement with quicker counter-attacks. The change allowed the defending team to pass the puck to out of their own zone up to the red line, instead of being required to skate over the nearest blue line then pass the puck forward. In the late 2010s, there were many goals being reviewed, due to a new Offside review system. There were complaints about how it affected the flow of the game. It is ruled differently now, where a team may request a review after a goal is scored during a play that team considers to be offside. If is ruled not offside, the goal counts and the team requesting the review is assessed a minor penalty. See also Icing References Ice hockey rules Ice hockey terminology Ice eo:Ofsajdo#Glacihokeo