Patrick Mahomes and the Kansas City Chiefs meet Josh Allen and the Buffalo Bills on Monday. Kickoff is set for 5 p.m. ET. Kansas City is a 5.5 point favorite and the Over-Under is 56 in the latest Chiefs vs. Bills odds from William Hill. Before making any Bills vs. Chiefs picks, you NEED to see what SportsLine senior analyst 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 58-39 on his against-the-spread NFL picks, giving his followers a profit of more than $1,500.

He also has a sharp eye for the Chiefs' tendencies, going an INSANE 9-1 in his last 10 against the spread picks involving Kansas City. Last week, when the Chiefs laid 13 at home to the Raiders, Hartstein was all over Las Vegas. The result? Raiders 40, K.C. 32. Anyone who has consistently followed him is way up. . 

Now, he has dialed in on Chiefs-Bills and released a confident against-the-spread pick. We can tell you Hartstein is leaning Over on the total, and he's also found a critical X-factor that has him jumping ALL OVER one side of the spread! You ABSOLUTELY need to see it before you lock in your own picks.

So who wins Chiefs vs. Bills on Monday? And what critical X-factor makes one side of the spread a MUST-BACK? ... Join SportsLine right now to see which side of the spread you should be all over on Monday, all from the seasoned expert who's 9-1 on picks involving the Chiefs!