The College Football Playoff was supposed to provide some certainty in a sport that, for too long, based its rewards on unreliable polls. And to the extent that there's no debate over the team crowned as national champions, it's worked. But if there's one thing fans have learned over the last few years, it's that little in modern college football is certain. And after one round of expansion, from four teams to 12, there's now more discussion and debate over the next round of growth. Some, including many fans, are happy leaving the field at 12. The SEC, arguably the most powerful conference, wants to move to 16, while maximizing the number of at-large teams. That would, in their view, allow for more teams to reach the field based on strength of schedule instead of conference affiliation. Strength of schedule=more SEC teams, the thinking goes. Then there's the Big Ten, Big 12, ACC, and independent Notre Dame.…