Abstract: A computerized stitching apparatus that automatically controls thread tension is disclosed. In one embodiment, at least two factors are used to determine the desired thread consumption for the next stitch. A thread length encoder is used to determine the amount of thread actually consumed for a particular stitch. The operator must enter a desired thread length ratio or an equivalent factor related to desired thread length used for a particular stitch into the operator input device. Another factor such as speed, stitch length, fabric thickness, or stitch angle change is used with at least the operator's input to determine the desired thread consumption. The tension of the thread is adjusted by the stitch control system which will affect the actual thread consumed for the particular stitch.