Systems and methods for computing sign disagreement between Le and La signals may implement one or more operations including, but not limited to: receiving an extrinsic log likelihood ratio (LLR) value; incrementing a sign-disagreement counter according to a sign disagreement between the extrinsic LLR value and an a priori LLR value; providing a value of the sign-disagreement counter to a binary short media defect (SMD) detector.