Alabama is the defending national champion and the top-ranked team in the land heading into this season.It has won nine straight season openers under coach Nick Saban, including victories over Michigan, Virginia Tech, West Virginia and Wisconsin.And it won both of its games at AT&T Stadium last season, including beating Michigan State 35-0 in the College Football Playoff semifinals.So, yeah, there's a pretty good reason the Crimson Tide are favored by 11 1/2 points against Southern Cal on Saturday in Arlington.But the depth of that challenge is what excites Trojans coach Clay Helton."You look at this recent surge of what they've done with national championships under Coach Saban.