The Alabama Crimson Tide will start their quest for a fifth national title this decade at 8 p.m. ET Saturday against Louisville on a neutral field at Camping World Stadium. Alabama is now a 23.5-point sportsbook favorite, down from the opening number of 25.5. The over-under for total points scored is 60.5, up from an initial offering of 60 at most outlets. Plenty of anticipation surrounds Alabama's two-man quarterback battle, as the hero from last year's title game and the seasoned incumbent will vie for the permanent job before a national audience. Louisville also enters a new era after losing its Heisman winner to the NFL draft. Before making any Alabama vs. Louisville picks, you need to see what SportsLine analyst Josh Nagel has to say.

What's more, he has had a keen eye for these two programs. Nagel boasts an impressive spread record of 8-1 in games involving these two clubs, including a 4-0 mark on Louisville. Now, Nagel has analyzed all the key details of Saturday's game and released a confident point-spread selection, which he's sharing over at SportsLine.

Nagel knows the Crimson Tide should have their annual abundance of five-star talent, but they do have several important questions to address. The primary one drawing headlines is the quarterback competition between Jalen Hurts, a two-year starter, and Tua Tagovaiola, the hero of last season's National Championship game. Both are expected to see extensive time Saturday as coach Nick Saban named them co-starters. 

Alabama has major shoes to fill on the defensive side, particularly in the secondary following the departure of its top two cornerbacks and safeties. Alabama has some experience up front, but must compensate for the loss of nose tackle Da'Ron Payne, a first-round pick of the Washington Redskins. The Tide return just three starters from a unit that led the nation in scoring defense at 11.9 points per contest last season.

Just because Alabama has been dominant doesn't mean it can cover a three touchdown-plus spread. Louisville's new quarterback, Jawon Pass, has the attributes of a pro-style pocket quarterback, the likes of which coach Bobby Petrino has preferred during his tenure. The 6-4, 230-pound sophomore went 23 of 33 for 233 yards and two touchdowns last year in limited action behind Lamar Jackson, who's now in the NFL.

Pass will benefit from an experienced offensive line and wealth of veteran playmakers on the outside. The major question for Louisville lies in a youth-heavy defense that returns just two starters and was a liability at times last season.

We can tell you Nagel is leaning under, but he has also identified the critical x-factor that makes one side of the spread a must-back. He's sharing what it is, and who to back, only at SportsLine.

Who covers Louisville-Alabama? And what critical X-factor determines the spread? Visit SportsLine now to see which side you need to jump on Saturday, from an accomplished analyst who's hitting 89 percent of his picks involving these teams.