There's a list, and the reason your rough street confused you is that the list only works relative to the block around it. Distress is a deviation from the neighbors, so grass at 10 inches on a street where everyone mows is a signal, and the same grass on a street where nobody mows is background.
The signals that hold up best are the ones that cost money or attention to fix and can't be faked: a tarp or visible patch on the roof, boarded or plastic-sheeted windows, a code enforcement or condemnation notice taped to the door, an overflowing or missing mailbox, gutters hanging off, a full driveway of uncollected mail or flyers, and utilities visibly shut off such as a removed meter. Your tarp house is a real one. Tall grass on its own is weak, it might mean somebody was traveling.
What you're really looking for is a gap between what the property needs and what the owner is doing about it. That gap usually means either no money, no proximity, or no interest, and all three make for a conversation worth having.
One thing that isn't obvious from the car: an occupied house with a maintained interior and a bad exterior is very common with elderly long-term owners, and those situations need care. There's a difference between contacting someone about selling and pressuring someone who's vulnerable, and the rules around unsolicited contact are getting tighter in several states. Keep your outreach plain, identify yourself, and stop when someone says stop.
Also photograph each one. In six months you'll want to compare.
