It looks like part of the grass burned by chemicals. What looks odd to me is that the grass at the sidewalk edge looks fine. What kind of grass do you have there?

Thanks for your help - I don't know what kind of grass it is. The seed that I buy is primarily a mix of tall fescue, rye and kentucky blue. But the funny thing is that I don't use any chemicals at all - well at least in the last 12 years. The only thing I put down is milorganite - an organic fertilizer.

The first photo looks like mechanical (physical) damage from tires - suspiciously near where a tire would hit, properly linear and you can almost see the tread patterns.

Not sure the other photos are showing the same thing.

Oh, how fun. Mystery damage. But not really a mystery in this case, I'm thinking. Mechanical damage is out; the tracks are clearly from mowing after the fact. Chemical damage seems inconsistent with the patterns.

I can guess your weather pattern from here but....can you tell me if spring was very, very wet in OH? Followed by a hot summer but still with plenty of rain or irrigation? Now with the characteristic warm fall that's still got us all in a funk?

Cheer up, at least you're missing the bomb cyclone* we're getting. It's pouring rain, but at least I was at work at 4:30 and home by 3 this afternoon.

But I digress. I'm thinking late-stage fungal issue. It's most likely going to go dormant for winter the instant temperatures drop out of the range mesophiles (middling temperature loving creatures like most summer/fall fungal diseases and humans and whatnot) like. You can see if the very near (within a half inch) surrounding grasses show disease characteristics like yellowing blades, white threads on the grass, or other unusual symptoms like odd growth.

I might be inclined to treat it, but this looks like it went so fast and so far I'm not entirely sure what disease it is at this point. A wide-spectrum fungicide would probably be best, which would be most of those on the shelf at the big box store. They're designed for homeowners to fight a wide spectrum of diseases without being too picky.

I'm not entirely happy with that answer--the other option is to ride it through spring and see if General Winter takes out the disease for you. Or see if it can thrive in cold weather under snow and destroy even more lawn when you can't do anything about it...

* Most of the time I seriously want to slap weather people for needing to hype up every single rainstorm with a name or fancy title just because the pressure drops 25 millibars.

If you run a garden hose in that plot of grass does the water pool up where that brown stripe is? Maybe there is a low spot caused by a car running on the grass in the spring, or something like that.... just spitballing.