A boot/binding system for a snowboard wherein the boot includes a sole and transverse bar having two ends. A binding includes a base defining a horizontal plane and a median plane. The binding is selectively fixed to the board in a plurality of positions and is pivotal about an axis which is perpendicular to the horizontal plane and intersects the horizontal plane at point O. The binding includes two vertical plates arranged substantially parallel to the median plane, each of the vertical plates including a vertical groove into which one end of the transverse bar of the boot is insertable. The ends of said bar are held inside each groove by a pivoting cam elastically held in position. A first region of contact of the bar end is in contact with a front wall of the groove and the first region of contact is contained in a normal plane formed by the front wall of the groove. The normal plane is arranged perpendicular to the median plane and to the horizontal plane and the first region of contact is located at a distance in the backward direction from point O of between 0 and 30 millimeters. A second region of contact of the bar is in contact with the cam and the second region is contained in a parallelpiped volume defined by three plane sets, the plane sets comprising: (1) an M plane and an M' plane which are situated behind and parallel to the normal plane, the M plane and M' plane being respectively at a distance of 5 and 10 millimeters from the normal plane; (2) a Q plane and a Q' plane which are situated above and parallel to the horizontal plane, the Q plane and Q' plane being respectively at a distance of 12.5 millimeters and 22.5 millimeters from the horizontal plane; and, (3) an R plane and a R' plane, which are parallel to the median plane and are coplanar with each of the vertical plates, the R plane and R' plane being from 2 to 8 millimeters apart.