I meant like at a farm coop. Maybe that’s what you meant too. But when I had mine tested they were able to tell me the exact amount of each nutrient it needed for grass growth, proper ph, etc. I was just thinking that as much rain as you had that it shouldn’t have been that hard to keep your grass green. Makes me think it needs to grow a better root system. Could be wrong but that would be my first attempt. Also do you aerify the soil each year.
I always thought that I did all the right things with my grass but my first soil test showed me that my soil was highly deficient in some areas, most notably nitrogen.
The puzzling thing for me about your situation was that it seemed like you got a lot of rain. But then again you say your soil drains really well. I guess you could make the big jump to a warm season grass but you’ll have a brown lawn from Oct to May.