A saddle stitcher for printed products includes a saddle chain; a stitching machine; a controller; an ejector; and a delivery system. The delivery system includes: at least one lower conveyor belt and one upper conveyor belt; and at least one deflection roller for the lower conveyor belt, the at least one deflection roller being arranged in a radius. The lower conveyor belt has a first controllable self-propelled drive. The upper conveyor belt has a second controllable self-propelled drive. The controller is configured to separately control the first controllable self-propelled drive and the second controllable self-propelled drive. The controller is configured to provide a control that is exact to a cycle and is adjustable according to a thickness and a format of a respective printed product in a product flow.