A method for detecting defects in devices that are fabricated in repetitive patterns upon the surface of a substrate by the, repetitive utilization of masks and similar devices. A mask flaw will become manifest in a series of defective devices as the mask is successively utilized. The detection of repetitive defects is undertaken by determining the electrical resistance of devices in a group, such as a column, fabricated upon the wafer surface, where the repetitive defect will occur multiple times. The mean electrical resistance of the group is determined and a percent deviation of each device from the mean is then determined. The percent deviation of all of the devices in the group are multiplied together to create a multiplied percent deviation number and the multiplied percent deviation number is then compared with a figure of merit value to make a determination of whether defective devices exist within the group.