Tell us a bit about how much/often you water and how. In those browned out areas, press a screwdriver into a few spots and see how easily the screwdriver goes into the soil. Watering/compaction are 2 things that come to mind immediately with this scenario.
What did you see happen over the summer...did it slowly turn brown, was water collecting, lots of foot traffic? Tell us what you think is different between your lawn and the neighbors or this year versus the past years when it looked better. More pics would help also.