The Indianapolis Colts visit the NFC South-champion New Orleans Saints on Monday Night Football. Kickoff is set for 8:15 p.m. ET. New Orleans is a nine-point favorite, while the Over-Under for total points scored is 48.

Before you make any Saints vs. 49ers picks and NFL predictions, see what SportsLine's No. 1 NFL expert, Larry Hartstein, has to say. 

A former lead writer for Covers and The Linemakers, Hartstein combines a vast network of Vegas sources with an analytical approach he honed while working for Pro Football Focus. Last year, he went 61-47 in the NFL, and this year, he's even hotter. Entering Week 15, Hartstein was a scorching 48-28 against the spread this season, a 63 percent cash rate that's returned his followers more than $1,700.

In addition, he has a particularly keen eye for the Saints. In fact, Hartstein is a BLISTERING 26-14 in his last 40 picks for or against the Saints! Anyone who has followed him is WAY up.

We can tell you Hartstein is leaning Over on Monday Night Football, but his much stronger play is on the spread. Hartstein has found a crucial x-factor that has him going BIG on one side. You ABSOLUTELY need to see it before locking in your own picks.

Who wins Saints vs. Colts on Monday Night Football? And what crucial x-factor makes one side of the spread a MUST-BACK? ... Join SportsLine right now to see which side of the Saints vs. Colts spread you need to back on Monday, all from the acclaimed expert who's an impressive 26-14 on Saints picks!