They will have a thousand horror stories that you can prove wrong, but it does not matter, it is their experience telling them otherwise and your fancy equations do not matter.I can bet that the investors that give you these excuses are very conservative and do not want to risk their hard earned capital.

Unfortunately in all Countries of the World, "Ignorance of the law" is not an excuse.

It was always one excuse after the other but it was livable and i ended up getting my own AC instead that i could take with me.

Don't accept their excuses for why there are dings on the credit.

I even offer to check for them, so they have no excuse. 

the tenant's excuse was that her lawnmower broke so I paid someone to do the yard work and paid the City's fine and then send her an invoice to pay me back within 10 days and she did.  

Understand rights of quiet enjoyment of possession, how and when you contact a tenant can quickly go to breach of their rights of quiet enjoyment, don't bug them, don't drop by with notices of mickey mouse inspection excuses to go inside, too much of that will cause problems.

Excuse the language, but it seems that these bugs are quite frustrating.

@Steven Gesis  My spelling is not up to par today.. but I have an excuse I am in Maui and well those mai tai's are pretty nice.. just living the life of a RE investor  LOL.

Frederick area (excuse my split msg)