The chances were slim. Considered impossible actually. To guess an 

ethereum

or 

bitcoin

address' private key. You could just guess numbers... because that's all a 

private key

was. And if you got the right one then the 

Blockchain

gave you access as though you were the rightful owner. Because to the blockchain it didn't discern between who the right owner was. There was no right owner. Whoever had access to the private key and could prove that they had the private key was the owner.

Ethan Wilkinson had created a script that orchestrated a series of super computers at his university to guess private keys. It would take a number, calculate its public address, and check whether that address had any funds associated with it. Except it would do this at about 12 billion guesses per second. The script only powered up the super computers between 8 pm and 5 am. The university used them throughout the other day. Within six months the university would have tracking on such a script so Wilkinson had to stop by then. But he might land on some large accounts.

What were the chances though? Of finding even one account? Low. It would be like dropping a basketball from 

Spacecity

 and hoping that it went into one of the hoops here on earth. Possible? Yes. Something to count on? No.