I have a much simpler strategy that doesn't require any fancy charts: buy when you find a great deal in a great neighborhood that you can reasonably afford to hold through thick and thin.

It is glue down thick vinly/rubberized plank flooring that is very easy to install and almost indestructible. 

It is 6.3 mm thick, waterproof core and under layment, and locking joints. 

I suggest 13 mm or even 25 mm thick materials planks.

It looks like lathe and plaster which means the walls are most likely a thick mud wall with plaster embedded with wire which is a bear to remove, hopefully that quote is for a full gut and replace, but I would just update the floor, have the wall tile painted, tub glazed, new shower fixture, vanity and accessories like towel bar, shower curtain. 

Replace the wax ring with an extra thick ring and you should be fine.

The criminals here a thick along with aggressive homeless meth heads!

Also I see new money being invested as investors are buying wear houses and converting Into residential, I am looking to add to my portfolio bigger properties  but I don't see many 5+ units in inventory, but over all I think if you got thick skin it's a great place to create a passive income portfolio 

I am a litigator and investor with very thick skin.

I'm just glad that I'm not the only one who found the RDPD book lacking; as opposed to me just being too thick to understand the message.