The Urbandale $1 million Powerball winner Robert Winburn said his system finally paid off after 20 year's trying. But Silverites would be astonished at how long it took and how wackily his 'system' was designed.

Winburn said he assigned numbers to the letters of the alphabet, and uses the corresponding numbers in his last name as his Powerball numbers. But it took two decades of fruitless trying before it paid off.

Winburn said he didn't know that he had a $1 million-winning ticket in 2014 until he scanned his tickets Sunday using a self-checker at an Urbandale grocery store.

The lucky ticket was purchased at Git-N-Go, Hickman Road in Urbandale. PHOTO: Google Maps

"I put the first three tickets in and no win," Winburn told lottery employees as he claimed his prize at the lottery's headquarters in Des Moines. "Then the winning one came up. I just kind of glanced at it."

Winburn said he scanned his ticket a second time to double-check. "I did tell the guy next to me, 'I don't believe this,'" he said.

"And he leaned over and I did it again and he says, 'Sign it and get the heck out of here.'"

Imagine how much faster Robert would have won with the Silver Lotto System. He only did one thing right - played consistently with the same numbers.

But he failed to use the powerful Silver Lotto System formula that has brought thousands of winners prizes every week.

Watch a news clip of the win below.