In the scam one person is making loads of predictions knowing that some will pay off. In this story, lots of people are making predictions and again, the chances are some of them will be right. Read the comment I replied to, his point was exactly the same as the scam's logic, which is basically that if enough monkeys spend enough time with typewriters... etc.
There's a very important difference that you're missing. In the scam you're applying you're random machine over all possible results. In the sabermetrician example, the random machine is being applied across methodologies of picking prospects, ie bunch of different "moneyball" hobbyists trying out different stats and weights to rank players. The end result is the possibility of the discovery of a very good methodology that has found stats that traditionally are not important.
But it takes more than one result to tell whether the methodology is good or if it was just lucky - otherwise it's just a guy tossing a coin once and saying "see, I predicted heads!"
