The greener sections have shade for some evaporation protection and/or on a downhill slope. That makes me think it's a water issue. When was the last time you checked your sprinkler output?

Height also looks kind of long. What is you height of cut?

That is odd. I see some surface rooting in that first pic where stolons are sticking up, broken rather than cut & the verge of a hill like that is prime thatch collection territory. What is your height of cut & are you bagging your clippings? It could also be as simple as a shade issue from that fence. Can you stick a Phillips screwdriver in that spot without effort?

Yea I see what RJ says about the thatch area. It's like a rut a foot or so away from the fence.

So I'll try to answer all the current questions and see if this helps.

The front yard gets full sun 80% of the day and is only shaded in the late afternoon and evening.

The cut is maintained at 3/4"

There is a rut along the fence due to the repetitive path the fence causes me to take, hence my changing patterns every mowing which is every 3-7 days as needed. I'm never cutting off more than 1/4"

Some of what you're seeing with the rut area along the fence is also a sod seam that when I aerated this spring, I also top dressed with mushroom compost and used a drag mat to rake it into the low spots and seams. This was a bad seam and has a buildup of compost still visible.

I can insert a screwdriver into most all areas, some parts are tough I think due to the rocky, clay soil in upper SC.

I was considering aerating again and overseeding, this weekend or next is now a good time to overseed Bermuda or should I wait until the spring?

I have not overseeded yet, that was just a thought.

And I've just checked and forgot I recently raised my mower height to 1-1/4" over the last week and a half. Also these pics have been taken when the lawn is due for a cut, because the problem is more pronounced when its grown for several days.

Here is a picture of the mower I'm using and my brothers Zoysia lawn we cut with the same mower.

I have did plant my back yard with Bermuda seed on August 1st and here's a picture of that after 27 days or regular watering.

And I don't know what type of Bermuda Sod I have, the builder put it down when we bought this house last year.

As for the seed in the back yard I've used about 10lbs of a 15lbs bag of Vigoro Bermuda seed blend.

Since it turned out so well is the reason I was considering overseeding with this product.

Do you think it would hurt or just unnecessary given the right care?

Aeration will do plenty by itself

I've never seen a clear answer on when to aerate, can it be done in fall and spring or should I just choose one?

Spring or summer. Once temps drop below 80 in the daytime it will not recover well

To be clear to anyone else reading now or in the future, Bermuda responds to mechanical stimulation like aeration & verticutting by surging growth. This does NOT happen with other grass types.

Is verticutting the same thing as dethatching?

The type of bermuda seed is on the back of the bag if you still have it.

Completely agree with RJ on mechanical stimulation of bermuda. I'm currently plotting my strategy for next year. A number of golf courses I researched verticut and sand every 2 weeks. The core aerate every month. With that in mind I'm looking to verticut at least three times and aerate x2 next year.

From my research, if the lawn is healthy, stable and mature (2-3 years old) you can verticut of aerate anytime during the growing season. So we could in theory be safe upwards of a week or two before out first frost dates. This Winter is my lawn's 1st so I don't know if/when my lawn will go dormant.

Your backyard look good. You should do a blanket application of Celsius and Prodiamine (or Dimension) very soon. Kill those weeds and let the bermuda spread a little more be it gets cold. Make sure to do pre-emergent on the front lawn as well.

You have a good mower. Check your blade's sharpness and the rolliness of you roller (does it freely/easily spin). Your grass may be laying down longways and not being cut. Even though the mower is set at 1. 25" the actual length of the grass may be long. If you got a few hundred dollars laying around getone of these, otherwise any dime-store ruler will do. Make sure you lightly comb the grass and stand it up before you measure it. You probably can't cut in 3-4 different direction up by that fence which may lead to the grass laying down lengthwise.

I would try focusing a little extra irrigation in that area to see if it improves. Also if you hand water this area does it soak in or does it evaporate before it can infiltrate the soil? A good test to get a visual of water penetration is to water the spot heavily by hand, wait a little while until the water is no longer visible then pull a plug and see how deep the water penetrated. When is the last time you've had a good rain? My soil is nearly straight sand so I have areas in my lawn that tend to become hydrophobic after extended periods of no rainfall (localized dry spots). When this happens these areas will not absorb much of any amount of water applied unless I intervene with some localized aerification or perhaps the use of a soil conditioner. Aerification definitely improves water penetration and soil conditioners can be useful as well. From my experiences with my lawn, a good steady rain alone will help to begin alleviating the case of hydrophobic soil or either aggressive hand watering a few times daily coupled with aerification until the area shows signs of improvement.

Baby shampoo or jet dry will soften up the ground really well if it's too late in the season for aeration. Verticutting & dethatching are not the same, though very similar--verticutting cuts fairly deep, maybe an inch or deeper. Dethatcher only scratches the surface down to a 1/4" or so & doesn't stimulate the root zone

Update after making some changes to the watering schedule and getting a soil sample. It's starting to even out a bit with the color.

Apparently I need to change my fertilizing schedule.

Good job. That looks a lot better.

For future reference I found out that the Vigoro Bermuda seed is a mix of Bargusto and Transcontinental.