Marco Luciano is all of 19 years old (he turns 20 in September) but he's rated by FanGraphs as the no. 2 prospect in the Giants organization. He signed as an amateur free agent when he was 16 years old. You can do that in the Dominican Republic (Luciano is from San Pedro de Macoris) and other places like Venezuela. You have to be 17 if you are from the United States. The Giants were willing to risk $2.6M on this teenage phenom so it should be fun to follow his progress.