They learned it from Gonzaga.Despite what you think of St. Mary's non-con, it is ranked 43rd for non-con SOS. Iowa State's is 121st. They game the system by limiting the terrible teams they play in the non-con. Once they have a solid non-con RPI they roll up wins on easy teams and the RPI isn't going to drop for winning lots of games.
What I don't get is why they are ranked. You can trick the computers, you shouldn't be able to trick writers that cover the game. Yet they do.