Those who have had experience, were there signs at the beginning that you may not have chosen a good tenant, or is it a complete gamble and you just don't know what you're going to get.  

Properties that are unique in their neighborhood are notoriously difficult to calculate for accurate investment value.Do you want to be left stranded, committed to buy at a price the Seller already thinks is the best net-price they can get, and you would be gambling it wasn't?

Similarly, if you're the riverboat gambling type, you can try looking into an equity deal where the buyer pays you X% of final sales price and/or a percentage of rental income if buy & hold.

@Clay ChandlerGood question and they can be, but you have to be wary of uncontrollable condo association fees.

The gamble is whether the annual loss on the rental scheme will be mostly covered when I eventually sell the condo.  

What do they care if I buy poorly and lose my shirt down the road.Again, just following what the market and others are doing sounds like gambling , not investing.

I took gamble needing to get  the rent coming in and almost 4 years later they have been the best tenant.

On top of that you should know exactly who is going to buy or rent it from you and all the terms of the deal.Real estate investment is not gambling.  

But I have read and feel that that is almost like gambling.

If not, are you just looking to gamble?