Buying real estate without debt...

[Bob Ewoldt]

All, I'm new to real estate investing, but I'm good with numbers (I am an accountant). Here's my newbie question...

I listen to Dave Ramsey regularly (and I see that there are several on here that do as well), and he recommends buying investment real estate without debt. When I run the numbers on deals that I see, I see much higher returns with a modest down payment than buying with cash.

I know that there's a risk factor overall, but I can't find anywhere that says how to calculate mortgage risk into your deals.

Questions:

1. Is there a formula for risk when evaluating a RE deal?
2. I've seen people on this forum say that putting all your money into one property is risky, but couldn't the opposite also be true (that dividing your personal and business focus on multiple properties is also risky)?