Nate Pfenenger took his chances, rolled the dice and came out a winner.Specifically, he turned 20,400 black dice into an intricate, larger-than-life-size mosaic portrait of Venerable Father Augustus Tolton.“I didn’t think it was going to be a big thing,” said Nate, a senior at Fr. Tolton Regional Catholic High School in Columbia. “I just thought it would be a really fun and memorable art project.”