Bayer fungus control gets a good rap around here.

what causes it? Is there anything I can do to not provoke it from forming in the first place. Why did it decide to pop up where it did I wonder?

Thanks.

There's about a million ways it forms. Even the healthiest grass isn't immune, but high moisture & low airflow are a sure bet

finally, got the bayer...is there a good time of year to put it down? Multiple times throughout the year even?

I don't like to use fungicide period because the major class of beneficial microbes in your soil are fungi. However, there are times when something must be done. If I was a fungicide user, I would not use it preemptively in order to spare the stress to the soil microbes. I would only use it when a disease is present.