In this paper the evaluation of matrix elements for a vector boson decaying into n partons (n less-than-or-equal-to 6) is presented. For this purpose recursive techniques and Weyl-van der Waerden spinor calculus are used. By appropriately crossing partons the amplitudes can be used to describe the production of a W and jets. The four-jet case is of particular interest as background to interesting physics signals. Numerical results are given for present and future accelerator energies. Also the signal versus background question for top quark search is briefly discussed.