He's in Michigan.  Should not be St. Aug or Bermuda.  I think it's a combination of crabgrass and goosegrass.  They grow from seed every year.  Goosegrass is a really nasty weed grass, with a prostrate growth habit, radiating out from a light colored center.  Best to dig it up with a dandelion digging fork.  Raising the mowing height helps to control it, or you can carefully spray the center of the clump with glyphosate mix, then pull it out more easily a couple weeks later.