Entering offensive zone - Hockey drill diagram
"The blue lines divide the rink into three zones. The central zone is called the neutral zone or simply centre ice. The generic term for the outer zones is end zones, but they are more commonly referred to by terms relative to each team. The end zone in which a team is trying to score is called the attacking zone or offensive zone; the end zone in which the team's own goal net is located is called the defending zone or defensive zone.
The blue line is considered part of whichever zone the puck is in. Therefore, if the puck is in the neutral zone, the blue line is part of the neutral zone. It must completely cross the blue line to be considered in the end zone. Once the puck is in the end zone, the blue line becomes part of that end zone. The puck must now completely cross the blue line in the other direction to be considered in the neutral zone again." [Ice hockey rink. Wikipedia]
The hockey drill diagram example "Entering offensive zone" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Hockey solution from the Sport area of ConceptDraw Solution Park.