The present invention relates to a method and a numerical analysis for predicting golf ball launch conditions, e.g., velocity, launch angle and spin rate. By acquiring pre-impact swing conditions, e.g., club speed, rotational rate and ball hit location, along with pertinent club features, e.g., moment of inertia, and ball impact features, e.g., normal and transverse forces as well as time of contact, the method can predict the resulting trajectory and launch conditions of the golf ball. The predicted ball launch conditions and trajectories can also be used to modify one or more properties of the golf ball or golf club. The time of contact measurements can be corrected to account for drag force.