Any Alternatives to the "South of Shaw" Rule?

I moved to Fresno a few years ago, and during that time, I've lived in the area around Fresno State. However, I've had the opportunity to visit some of the other parts of Fresno, and I used to work by Blackstone and McKinley.

I've heard the "south of Shaw" recommendation ever since I moved here, but it feels too restrictive, especially because most blocks down to Dakota (save for islands like the stretch of Bulldog Lane by Bulldog Stadium) look and feel very suburban and safe to me. I've been through them many times, at all times of day. Other folks on the subreddit who seem to have more experience here than myself have also suggested the rule paints too broad a brush.

I've noticed that things start to noticably change around Shields: the tweakers become more visible, the houses are noticably older, simpler, and smaller, and the people start to look more the ghetto residents I'm used to. That's where I start noticing that I should be a little more careful with my stuff.

But as a person who hasn't lived in central or south Fresno, I ask you guys, what would a good alternative warning be?