Of course not, at least not for any sustainable period. An analogy would be the lottery. Sure, a few strike it rich without ANY edge, but what were their
odds.....somewhere around 17 million to 1, I suppose. Gamblers ruin would certainly follow with an attempt to survive on lottery winnings.
To sustain a profitable betting future, one MUST have a method, and there are several.
Being somewhat analytical, I personally choose to model. As an example, yesterday Philly was favored by -164 with Hamels pitching. I loved everything about the game, but my model had the odds at Philly -130. Fortunately, I passed and Philly got beat. But the point here is about a quantifiable edge. Because baseball is driven by moneylines, in this case I didn't have an edge. Should I pay $164 dollars for something worth $130? Sure, I may have one that game but in the long run I will lose betting games with a negitive edge.
I suppose in summation, without a reliable model, I may have placed that bet and many others without knowing if there was an edge or not.