A deformable basketball goal support structure configured to selectively engage a rigid upright member and allow for adjustment of the height of a basketball goal above a playing surface. The basketball goal support structure has a backboard and an attachment member configured to selectively connect the goal support structure to the upright member. At least one support arm pivotally attaches between the attachment member and the backboard. Preferably, a pair of first support arms and a pair of second support arms pivotally attach between the attachment member and the backboard. The backboard includes a support frame having an internal periphery sufficient for receiving at least a portion of the attachment member and the support arms. The attachment member and the support arms, in combination, form a deformable parallelogrammic structure positionable between an extended position for game play and a collapsed position wherein at least a portion of the attachment member and the support arms are positioned within the internal periphery of the backboard and lie substantially flat against the backboard. The attachment member and the support arms may be generally disposed in the same plane as the backboard thereby forming a compact system when packaging or storing the basketball goal support structure.