A method and system for optimizing coding gain that alters the backsearch buffer length and/or the input buffer length of a decoder in response to one or more transmission performance characteristics of the system. The performance characteristics are monitored to determine the performance of the system. The measured transmission performance characteristics are used to control the lengths of the backsearch buffer and the input buffer. The measured transmission performance characteristics along with the backsearch length and/or the input buffer length are analyzed and compared with simulated decoding results. In accordance with the simulated results, the system determines the optimal size of the backsearch buffer and the input buffer needed to achieve a desired performance target. The system adjusts the size of the backsearch buffer length and/or the input buffer length to equal the determined optimal lengths.