The B skip is nearly identical to the A skip, but first extends the leg forward. This extension of the leg dynamically stretches the hamstring and then allows you to really emphasize the backward pawing motion as your foot lands on the ground and pulls through. Get into the rhythm of the A and B skips by listening to the pattern of sound your feet make as they contact and scuff the ground, pawing backwards. Use the same arm motion during this drill as you use while running.
More running drills: