You can only post one photo at a time if you are attaching photos to your post. You can post another photo in the next message if you want. Just try to orient it so that we don't have to look sideways or upside down.

The experts will want the following basic information before they can help much:

Where do you live?
What is your watering schedule? How often and how much?
What kind of grass do you have?
What do you do in terms of lawn care?
How high do you mow the lawn?
How long ago did the patches start to show up?

That should be a good start for the people who can help you further.

It looks like they leave in Queensland Australia (based on profile/zone shown)

So likely a warm season grass of some sort (which one will be helpful)

The rest of the questions above will be very helpful!

Also, what else have you done to the lawn like fertilizer, weed killer......etc? And all the questions daniel asked. From the initial pictures it looks like Couch grass which is your equivalent to our bermuda grass. The more info the better!!

The op seems to have forgotten about this thread.

Or is enjoying a much-deserved happy New Year and will be back. Personally, I plan on possibly getting out of my PJs and into actual street clothes sometime tomorrow. Maybe.

Hi Guys. You're right well deserved NY break.
We live in Brookwater QLD postcode 4300.
I mow the lawn once a week on no. 7 setting.
I water the lawn once a week with a sprinkler for about an hour.
It is couch grass.
We moved into our new home in July and as the home was new the lawn needed a lot of water as it was dying. I fertilized straight away and it came good. These patches appeared in October.
I also sprayed for grubs in October thinking it was that.
The lawn at the front of the home is excellent.
Could this be root rot?
Thanks everyone in advance

Sorry bit more information.
Our home backs onto the 18th hole of the Brookwater golf course.

Is there a lot of thatch or shade? Does the area get 6-8 hours sunlight a day?

Definitely gets at least 8 hours of sunlight. no shade.

What kind of mower do you have and what height is #7 on your mower? When was the last time you fertilized and what did you use? I think right now you may be mowing too high/not often enough and may need to water more often too. I doubt you have thatch since it is a new lawn and this is the first year for it. Can you get any close up pics?

If you want to check for grubs, get a pitcher or bucket of water with at least 1 gal/ 4 liters of water and add some dish soap to it and make it nice and soapy. Pour that in an area you think you have grubs and you should see them come up to the surface in about a minute or so. Another indication is if you have a lot of birds on your lawn eating.

"I think right now you may be mowing too high/not often enough and may need to water more often too."

Totally agree. That looks like bermuda that got a little too drought stressed and parts of it went dormant.

This time of year you should be watering once a week at a rate that equates to 2.5 to 3 cm, all at one time. What we usually tell people is to set out some tuna or cat food cans (about 2.5 to 3 cm tall with straight sides) in the lawn. Then turn on the sprinklers and time how long it takes to fill the cans. That will become your normal watering time. The only thing that varies is how often you watering. In the hottest heat of summer, the max frequency would be once per week. That tapers off to once a month in the winter. When you back off on the frequency and water deeply, you eliminate the possibility of root rot and almost completely avoid weeds.