NFL Week 5 ends at Soldier Field with the Chicago Bears hosting the Minnesota Vikings on Monday Night Football.

The Vikings are 3.5-point favorites over their NFC North rivals. The Over-Under, or total number of points Vegas thinks will be scored, is 40.5, the same as where it opened.

Before you make any bets on a prime time game like this, you'll want to hear what SportsLine Senior Analyst Larry Hartstein has to say.

In Week 3, when the undefeated Steelers visited the winless Bears, Hartstein was all over the Monsters of the Midway. The result: Chicago won outright, 23-17, as a massive 7.5-point underdog.

It was Hartstein's sixth correct pick for or against the Bears in seven tries. He has a unique feel for when John Fox's crew shows up with a big effort, and it comes from his vast network of Vegas sources and an analytical approach he honed during his years working for Pro Football Focus.

Hartstein knows that rookie first-rounder Mitch Trubisky will make his first start for the Bears on Monday Night Football. And he knows the North Carolina product can't be any worse than Mike Glennon, who threw more INTs (five) than TDs (four) and never had a rating above 90.

He also knows the Bears are 29th in points scored and 27th in points allowed.

But just because the Bears struggle on both sides of the ball doesn't mean Minnesota wins by more than a field goal.

The Vikings just lost rookie RB sensation Dalvin Cook to a torn ACL and must now turn to free agent acquisition Latavius Murray, who's banged up and averaging a putrid 2.7 yards per carry. Cook was averaging 89 yards per game on the ground and scored twice.

Minnesota has also been without QB Sam Bradford, who took first-team practice reps this week and could return on Monday night.

It's no surprise Hartstein is expecting a low-scoring game that goes Under, but what about the spread, which he's made his name picking?

Hartstein knows there's one huge x-factor that determines the point spread winner of Bears vs. Vikings. And SportsLine stat geek R.J. White, who's on a +1400 run, agrees with him.

So which side of Bears-Vikings should you take? Visit SportsLine now to see what huge x-factor determines the point spread winner of Bears-Vikings and see which team has a surprising edge you need to take advantage of, all from the analyst who's nailed six of his last seven picks on Bears games.