I see many investors saying they are buying properties with no cash-flow or even a negative cash-flow because they predict the market will continue to grow and they'll eventually gain a cash-flow and build equity.

All in for 10k, sold house for 36,500.Now here's the deal - I'm not disputing your model is most likely easier, more easily repeatable, and more predictable.

I'm bad at predicting them and even worse at predicting how society will handle it. 

Thurston county is predicted to grow by 100k residents in the next 20 years--that's 40%!

if looking for appreciation(terrible strategy) look further north, in florida, there are plenty of smaller communities that are predicted to grow with our aging population.

CapEx is difficult to predict.  

The trigger is different every time but it is going to happen problem is we can not predict what the trigger will be so have no idea when it will happen.Everything is now in place for a collapse to occur it's simply a matter of time.

We just can’t predict it with exactness.

Of those, all I know is that the property needs to have the capability of adding value to where I can refinance and get all my money back.It would be close to where I live because I want to be able to see the place regularly.I need to be able to predict the numbers ahead of time.

If 2008 happens again or it gets worse, no one can predict what will happen.