A basketball backboard consists of several components, including the focal point -- the basket. Backboards used for competitive play always have a white rectangle positioned behind and above the ring. The rectangle is an important feature of the backboard that players rely on during a game.
According to Section II of the National Basketball Association rule book, a transparent backboard must be marked with a 2-inch-wide white rectangle centered behind the ring. The rectangle must have outside dimensions of 24 inches horizontally and 18 inches vertically. The base of the rectangle must be level with the basketball ring. The top edge of its base is to be on an even plane with the top of the ring. The bottom edge of the rectangle's base must be 6 inches from the backboard's base.
The white rectangle serves as a visual target for basketball players when they shoot the ball, and it enhances the shooter's depth perception. Backboards in competitive play must be transparent, which can affect a player's judgment and accuracy. Having the white rectangle behind the basketball ring helps the shooter aim his shot. The white lines act much like the circles on a dartboard. They are visual cues that guide the eyes of a shooter to a target.
A common shot in basketball is the layup. During a layup, a player attacks the goal by jumping up and toward the basket. He then guides the basketball to the backboard and gently bounces the ball off of it. When a player bounces the ball off the backboard at the correct angle and with the right amount of force, the ball rebounds into the basket. The white rectangle is critical in helping players align their layup so the rebounding ball goes through the basket. A layup attempt that bounces off the backboard inside of the white rectangle is considered a high-percentage shot.
Nearly all backboards, especially those used for competitive play, come with the white rectangle already in place. Most backboard manufacturers affix the rectangle during production, since it is a vital feature of the backboard and its specifications are universal. If you have a backboard that does not have the white rectangle, you can apply one using the dimension guidelines. Use a 2-inch-wide red or white adhesive tape that is designed to withstand heavy use. Note, however, that placing tape on a backboard is not allowed in competitive play. This technique should only be applied on basketball backboards used for recreation.