Your lawn fertilizer guy is hilarious. Fire him now.

The problem is you. You're overwatering. See all those circles of dead grass? Those are typical of fungal disease caused by overwatering. When the disease shows up with circles like that, it is referred to as fairy ring. Your lawn fertilizer guy should know that, so since he doesn't, fire him. He's incompetent and should be in another business. If he's part of a large business, the business is inept in their training. I'm guessing they have already fertilized your yard once this year. If they have, be sure to fire them. They should have waited until the end of May to fertilize.

You can recover right now by using a fungicide. I don't use fungicides so I can't help you select one for your area, but I can help you with proper watering.

Deep and infrequent is the mantra for watering. Deep means 1 inch all at one time, not spread out over a week. Put out some tuna or cat food cans and turn on your sprinklers. Time how long it takes to fill all the cans. That will be your watering time, every time you water, from now on. My oscillator sprinkler on full sweep takes 8 hours to fill the cans. High flow inground systems take as little as 15 to 20 minutes to fill all the cans. You'll have to determine the time for your setup. As for frequency of watering, that depends (mostly) on the daytime high temperature. Of course Mother Nature will deliver Her dose of water, so you should be able to skip watering for at least a week after a soaking rain. There have been a few years recently when I did not water until June or July because of some well timed rain storms. This year is different for us. The ponds all around us are full, but my little area has been skipped over. Anyway, with temps below 70, deep water once a month. Rain almost always takes care of this. With temps between 70 and 80, water once every 3 weeks. With temps between 80 and 90, water once every 2 weeks. With temps from 90 to 100, water once a week. That should work. If you see the grass drying out at day 6 in the summer, set it for a 6-day schedule instead of 7 days. In NO case should you ever water established turf every day.

Also make sure you are mowing the grass at the highest setting. Correcting the watering and setting the mower up will fix your issues.

So the problem with the appearance was caused by you (overwatering). There's nobody else to blame as much as I would love to blame the lawn fertilizer guy.

Thanks. They set the watering when they turned on the sprinklers. We got a new company this year.

Let me guess, you've not been doing anything about grubs. Might be just a guess but that's how my lawn looks after it just took a hit of fall grub damage. Grubs are especially problematic if you've been watering all summer to keep the lawn looking good. I could be wrong but best to play it safe and put down GrubEx. It's active ingredient is pretty benign to the environment as far as pesticides go.

Also, if you've been using chemical fertilizers and have a watering program in place, you will definitely need core aeration once or twice a year. I would definitely take control of the sprinklers yourself!!! Use a smart sprinkler or just program it for irrigation as needed based on the weather you've been getting. Your lawn will tell you when it needs water.