The main principles being A. don't measure success or failure based on making money, base it on making the mathematically correct decision  B. know the numbers and probabilities, there's no such thing as certainty and C.  

The standard Cap Rate formula isNOI / Purchase priceergo, mathematically, a NEGATIVE CAP RATE IS IMPOSSIBLEassuming one does not buy into a negative NOI (sheeze)

Two years with the same tenant is better mathematically and finacially, because if your having to change out your tenants yearly, that's twice the amount of vacancies, if your using a PM then you'll have to pay them twice the amount of rent for the first month (Renter's Warehouse requires 1 month rent for example), if your managing the property yourself then that's twice the amount of showings at least and that's time which equals money, then there's twice the amount of maintenance to turn the property over for the next renter, etc......   

After receiving my degree in Mathematics from the University of Arizona, I became a Equity Floor Trader at the Pacific Coast and Chicago Stock Exchanges.

I enjoy math, and I'll tell you it's hard to find advanced mathematics that are useful for real estate.

However since Cash Flow is as an objective, OPM is apparently mathematically advantageous to decrease capital used per generated $1 of CF, depending of course on the interest rate and the down payment percentage. 

Account Closed It will take me a minute to decipher what you are mathematically presenting.

Please be careful with mathematical yield.

For the non-mathematically inclined, my stuff is still relevant to you.

Real estate is a much simpler mathematical model that moves at a glaciers pace in comparison.