The Kansas City Chiefs are undefeated and have covered every game this season. And even after 14 Week 4 games already played out, Chiefs quarterback Patrick Mahomes still leads the league with 13 passing touchdowns and a 137.4 QB rating. Now, the Chiefs put the streak on the line and head to Mile High for a date with the Denver Broncos on Monday Night Football at 8:15 p.m. ET. In the latest Chiefs vs. Broncos odds, Kansas City is favored by 3.5 after the line moved as high as 4.5. The Over-Under for total points scored is 54.5 after surging as high as 56.

On a game featuring these two teams, there's no better expert to hear from than SportsLine's resident Vegas legend, Micah Roberts. He has worked in the Las Vegas sportsbook industry for 20 years, including a 13-year run as Station Casinos' book director. Armed with an unmatched network of sources, Roberts has started the 2018 NFL season strong. He's on a 13-7 run on NFL picks and has been especially adept at games involving either of these teams. 

Roberts is on a strong 6-1 run picking for or against Kansas City and on a 5-1 streak on Denver games -- an amazing 11-2 overall record involving these AFC West rivals. 

Now, he's zeroed in on Broncos vs. Chiefs and released a strong point spread pick that you can only see at SportsLine.

Roberts knows it's difficult to find a weak spot in a Chiefs offense that has scored between 38 and 42 points in all three games. It certainly isn't the play at quarterback. Patrick Mahomes has been nothing short of spectacular, throwing for 13 TDs and no INTs. His QB rating of 137.4 leads the league.

Mahomes is surrounded by weapons that have been too much for defenses to handle. RB Kareem Hunt has gained 168 yards, WR Tyreek Hill has 310 yards receiving, and TE Travis Kelce has 229 yards. Those three have combined for eight TDs in just three weeks. 

The Chiefs' defense is allowing a robust 30.7 points per game, but much of that can be attributed to how quickly the offense scores. Three players each have two sacks to lead the pass defense -- DE Allen Bailey and LBs Justin Houston and Dee Ford -- while Kansas City is allowing 111 yards per game on the ground.

Just because the Chiefs have been overwhelming on offense doesn't mean the Broncos can't cover, especially at home. 

Roberts also knows the Broncos found ways to win their two home games, edging the Seahawks 27-24 and the Raiders 20-19 before hitting the road and falling 27-14 to the Ravens. 

Case Keenum, the prized free agent QB who led the Vikings to an 11-3 mark last season, has yet to find his stride in the Mile High City. He's thrown for 743 yards, three TDs and five INTs.

That said, Monday's date with Kansas City's 31st-ranked pass defense could be just what the doctor ordered. In fact, the Chiefs are allowing a league-worst 362.7 yards through the air per game. Broncos wideouts Emmanuel Sanders and Demaryius Thomas have combined for 35 receptions on 66 targets, and that 53 percent catch rate is likely to rise as the season goes on.

Von Miller leads a physical defense the likes of which Mahomes has yet to encounter in his young career. Miller has four sacks through three games, tied for the league lead entering Week 4. Denver's run defense ranks third in the NFL, allowing just 77.7 yards per game, which could make for a long night for Chiefs back Kareem Hunt.

For Monday Night Football, we can tell you Roberts is leaning toward the over, but he has uncovered a major x-factor that he says will determine the spread outcome of this game. He's sharing what it is, and who to back, at SportsLine.

So which side of the Chiefs-Broncos spread do you need to be on, and what is that major x-factor that has Micah Roberts confidently backing it? Visit SportsLine now to see which side is a must-back, all from the former Vegas oddsmaker and current veteran handicapper on an astonishing 11-2 streak on Chiefs and Broncos games.