Watch the Scufflin' Up online guitar lesson by Andrew Ford from Blues Bass Survival Guide
This is a quarter note walking shuffle. The bass line is more linear and pattern oriented, than angular with big intervals. The main thing here is the pivot technique used throughout the groove. I either go back to the root and use it as a pivot or use the 5 as the pivot. It gives a more bouncy feel to the shuffle. This has a standard blues ending that walks up chromatically from the major 3rd to the 5th then plays the 6 and 7th of the major scale, before landing on beat 4 with the octave A. Often whoever is leading will conduct this ending with a slight ritard(slow down).