  An alternative W mass estimator in e+e- -> WW -> qqqq events at LEP2 is
designed to optimize the balance between the statistical uncertainty and the
systematic uncertainty due to a possible Colour Reconnection effect. The
preliminary result for the total uncertainty on the W mass in this channel is
roughly 30 % lower then those obtained with the standard estimators, based on
the SKI implementation of Colour Reconnection. Also an indirect measurement of
the SKI Colour Reconnection model parameter kappa is inferred from the
difference between both W mass estimators.
