A set of golf clubs of the nullironnull type, each club having a head, said head having a rear face, said rear face having a cavity delimited by walls, namely at least one lower wall forming the sole and an upper wall, said upper wall having several faces, namely a rear face, an upper face, a lower face facing the cavity and lateral faces, in which several clubs of said set have a head which has at least one recess made in the upper wall and opening onto a single face of said upper wall, away from the upper and lower faces, and wherein, the volume and/or the position inside the upper wall of said at least one recess varies from one club to another within said set, so that the position of the center of gravity of each head varies from one club to another.