A control computer for a rolling train is supplied with prescribed stand parameters of a rolling stand of the rolling train. The control computer sets variables describing a rolling pass of the rolling stand that together with initial data of a flat piece to be rolled and the stand data describe the resultant roll nip and the asymmetry thereof. The initial data may be width, average thickness and average strength of the workpiece to be rolled. Based on the initial data, the stand data and the set variables an expected delivery taper and/or an expected strip sabre for the workpiece is determined. At least one of the set variables is manipulated to bring the determined delivery taper close to a desired delivery taper and/or the strip sabre close to a desired strip sabre. The manipulated variables are used to control rolling the workpiece piece.