Make sure the soil isn't super compacted in those spots...which if it's bare, it probably is. Aerating helps. On a bermuda lawn May-June is usually a good time to Aerate. Top dress those bare spots with a 50/50 sand top soil mixture. Mowing the bermuda more frequently will cause it spread the stolons horizontally and spread over the bare spots.
Ill check lowes for one of those aerater spike things. My bermuda has those little runners everywhere so I guess im good there
how about helping with draining? Aerate and add some sand?