The timeline in basketball is a line on a basketball court that is located in the center, dividing it equally into two pieces. It is also known as the half-court line, center line, or midcourt line. The timeline comes into play during backcourt violations and over-and-back violations.
The timeline separates the backcourt and frontcourt. Inbounds passes that occur after a made basket are done from the baseline of the inbounding team's backcourt. Once the ball is inbounded, the offensive team must bring the ball from the backcourt to the frontcourt within a certain amount of time:
In the NBA, this is eight seconds.
In college basketball, this is ten seconds.
If the team fails to move the ball across the timeline, a backcourt violation is called, and the opposing team is awarded possession via an inbounds pass. Backcourt violations are also commonly known as eight-second or ten-second violations. They often come about because of a full-court press.
Over-and-back violations occur when a team possesses the ball in the frontcourt and goes back into the backcourt. This usually happens via a pass from a player who has just entered the frontcourt to a trailing player about to enter the frontcourt.