You don't see an undefeated team open as an underdog this late in the season very often, but that's exactly what will be happening in Week 6.

The 5-0 Chiefs have opened as a 3.5-point underdog against the Patriots, marking the first time since 2013 that an unbeaten team has been an underdog this late in the season. Coincidentally, the Chiefs were also involved the last time this happened. As a matter of fact, oddsmakers don't seem to show much respect for the Chiefs, because they always seemed to be involved when it comes to an undefeated team being an underdog.

Over the past 15 years, there have only been five instances where a team was an underdog after going unbeaten through the first five weeks of the season and two of the games before this year involved the Chiefs. Here's a quick look at those games:

2003: Fifteen years ago, the 5-0 Chiefs went into Green Bay for a primetime game as a 2.5-point underdog. The Chiefs ended up covering in a 40-34 upset win.

2006: Peyton Manning's Colts didn't get too much respect in 2006 as they opened as an undefeated underdog in consecutive weeks. At 6-0, they were a 3-point road underdog to the Broncos in a game that they won and covered (34-31). The next week, the 7-0 Colts were an 2.5-point underdog to Tom Brady's Patriots in a game they won and covered (27-20).

2012: Six years ago, a 6-0 Falcons team was a 3-point underdog in a road game against the Eagles, who just happened to be coached by Andy Reid. The Falcons ended up covering with a 30-17 win.

2013: Finally, we have the 2013 Chiefs, who were a 7.5-point underdog in a road game against Peyton Manning's Broncos. The Chiefs didn't win or cover in a 27-17 loss.

The good news for this year's Chiefs is that undefeated underdogs have gone 4-1 both straight-up and against the spread (ATS) over the past 15 years.

The Chiefs opening as an underdog here is interesting for multiple reasons. For one, Reid is pretty much the only coach in the NFL who has had some serious success against Bill Belichick over the past few years. Since being hired by the Chiefs in 2013, Reid has gone 2-0 against Belichick, including the season opener in 2017 when the Chiefs covered as a 8-point underdog in a 42-27 win. The Chiefs also thrashed the Patriots 41-14 in 2014 in a game that led to one of Belichick's most famous phrases, "We're on to Cincinnati."

Speaking of Cincinnati, that's home to another interesting point spread for Week 6. The Bengals opened as a 3-point favorite over the Steelers, which marks the first time since 2014 that they've been favored by at least a field goal over the Steelers. The rivalry between the Steelers and Bengals hasn't been much of rivalry over the past few years. Since Andy Dalton's rookie year in 2011, the Bengals have gone 3-11 straight-up against the Steelers and just 4-10 ATS.

So what other opening lines look interesting this week?

Let's get to the rest of the early odds and find out.

NFL Week 6 early odds

(All lines from Westgate Las Vegas SuperBook, all games on Sunday unless noted. Keep in mind, the point spreads you see below represent the opening odds for Week 6. For the most up-to-date line on each game, you can click here)

Eagles (2-3) at Giants (1-4), Thursday

Opening line: Eagles, -2.5 points

The Eagles have dominated this NFC East rivalry over the past five years. Since 2013, the Eagles have gone 8-2 straight-up against the Giants and 6-4 ATS. Of course, if there's one time you might not want to bet on the Eagles, it's when they're a road favorite. Since Carson Wentz's rookie year in 2016, the Eagles have gone 2-6 ATS as a road favorite, which is the third worst mark in the NFL over that span. The Eagles have also struggled to cover the spread this year. Not only have they failed to cover in their past three games, but they're just 1-6 ATS in their past seven regular season games dating back to Week 15 of 2017.

Buccaneers (2-2) at Falcons (1-4)

Opening line: Falcons, -3.5 points

If there's one thing the Falcons will have working in their favor this week, it's that they'll be facing a rusty Jameis Winston. Winston will be making his first start of the season on Sunday after sitting out three games due to suspension. The Falcons have won three in a row in this series and have averaged 33.7 points per game in those wins. The Falcons have also been dominant against the NFC South at home. Since the beginning of last season when their new stadium opened, Atlanta has gone 4-1 both straight-up and ATS against the division. As for the Buccaneers, they're not a great team to bet on the road. Tampa is 2-10 in their past 12 road games (4-7-1 ATS).

Steelers (2-2-1) at Bengals (4-1)

Opening line: Bengals, -3 points

This game marks the first time since 2015 that the Bengals have been favored in a game over the Steelers. Of course, it does't seem to matter who's favored, because the Steelers always seem to win no matter what. The Steelers have won eight of the past nine games in this series and have gone 7-2 ATS in that span. However, the Bengals have been one of the safest best in football this year. Cincinnati is 4-1 ATS in 2018, which is tied for the second best mark in the NFL. The Bengals have also covered in five of their past six home games, including two this year. The last time these two teams played came in December 2017 when the Bengals covered as a 4.5-point underdog in a 23-20 loss to the Steelers.

Chargers (3-2) at Browns (2-2-1)

Opening line: Chargers, -1 point

Betting on the Browns used to basically be the same thing as setting your money on fire, however, that's not the case this year. In 2018, the Browns are 4-1 ATS, which is tied with the Bengals and Lions for the second best mark in the NFL. For some reason, Philip Rivers always seems to struggle against Cleveland. The Chargers are just 2-2 in their past four meetings with the Browns with those games being decided by an average of four points. This game will mark just the eighth time in the past 10 years that the Chargers have been favored in an Eastern Time Zone game. In the other eight games, the Chargers went 3-5 straight-up and just 2-6 ATS. One of those losses came in 2016 to the Browns, which happened to be Cleveland's only win of the season.

Seahawks (2-3) at Raiders (1-4) in London

Opening line: Seahawks, -2 points

Get your tea and crumpets ready because this week marks the first London game of the 2018 season. If there's one thing that's been true about London games, it's that the favored team almost always wins. Since the international series started in 2007, the favored team has gone 15-5-1 straight-up and 13-8 ATS, so advantage Seahawks. The Seahawks are 16-9-1 ATS after a loss over the past five years, which is the third best mark in the NFL over that span. As for the Raiders, they tend to struggle against NFC teams. In their past 20 games against the other conference, the Raiders are 5-15 straight-up and just 7-12-1 ATS.

Bears (3-1) at Dolphins (3-2)

Opening line: Bears, -2 points

If there's one time you should feel comfortable betting the Bears, it's win they're playing an AFC team. Since drafting Mitchell Trubisky last year, the Bears have gone 4-0 both straight-up and ATS when going up against the AFC. This game will mark just the third time since 2014 that the Bears have been a road favorite. In the other two games, Chicago went 0-2 ATS, which includes a 16-14 win over the Cardinals earlier this year, when they didn't cover as a 5.5-point favorite. One thing about the Dolphins is that Adam Gase seems to thrive as a home underdog. Since he took over as coach in 2016, the Dolphins have gone 7-5 straight-up as a home dog (7-4-1 ATS). Gase came to Miami from the Bears and will be coaching against his old team for the first time in this game.

Cardinals (1-4) at Vikings (2-2-1)

Opening line: Vikings, -9.5 points

The last time the Vikings opened as a gigantic favorite, they ended up losing. Specifically, the Vikings lost to the Bills 27-6 back in Week 3 as a 16.5-point favorite. Of course, that game kind of feels like an anomaly when you consider the fact that the Vikings are 7-3 ATS in their past 10 home games (8-2 straight-up). As for the Cardinals, traveling to Minnesota has been a nightmare for them. Since relocating to Arizona in 1988, the Cardinals have gone 0-8 straight-up in Minnesota and 2-6 ATS. This game will mark the second time this year the Cards have been an underdog of nine or more points. Back in Week 2, the Cards didn't cover the spread as an 13.5-point underdog in a 34-0 loss to the Rams. This game will mark the eighth time this season that an NFL team has been favored by nine or more points. In the previous seven games, the favorite went 4-3 straight-up and just 2-5 ATS.

Colts (1-4) at Jets (2-3)

Opening line: Jets. -2.5 points

This might not even seem believable, but since the beginning of the 2017 season, the NFL's best team when it comes to covering the spread at home has been the New York Jets. The Jets are 9-2 ATS in home games since last year and 6-5 straight-up. One thing to keep an eye on in this game is the Colts' injury report. The Colts were so beat up in Week 5 that they couldn't even fill their 46-man game day roster. The Colts only dressed 44 players in Week 5 and were down to 40 players by the end of the game.

Panthers (3-1) at Redskins (2-1)

Opening line: Redskins, -2 points

If there's one team Cam Newton has dominated in his career, it's the Washington Redskins. Since being drafted in 2011, Newton has gone 4-0 both straight-up and ATS against Washington. More recently, the Panthers have been a pretty safe bet as an underdog. Since the beginning of the 2017 season, Carolina has gone 5-3 both straight-up and ATS in the eight games where they've been an underdog. One thing to keep in mind about this game is that the Redskins will be coming off a short week after playing on Monday. Under Jay Gruden, the Redskins are 2-4 straight-up the week after a Monday night game.

Bills (2-3) at Texans (3-2)

Opening line: Texans, -8.5 points

The Buffalo Bills have turned into upset specialists over the past year and a half. Since the beginning of the 2017 season, the Bills have been an underdog of eight or more points a total of five times and they've WON three of those games outright. The Bills have also gone 3-2 ATS in those games. On the flip side, the Texans haven't been a favorite of eight or more points since 2013, when they went 0-3 ATS in three games (1-2 straight-up). If we look at more recent numbers, the Texans are 2-4 both straight-up and 1-4-1 ATS since the beginning of last season in games where they're favored by three or more points.

Rams (5-0) at Broncos (2-3)

Opening line: Rams, -6.5 points

If there's one thing Sean McVay knows how to do, it's beat an AFC team. Since McVay was hired in 2017, the Rams have gone 6-0 straight-up against AFC teams and 5-1 ATS with two of those covers and wins coming this year against the Raiders and Chargers. Under McVay, the Rams are also 6-0 straight-up when favored by six or more points, which includes and ATS mark of 5-1. This game will mark just the sixth time in the past 10 years that the Broncos have been an underdog of six or more points at home. In the prior five games, the Broncos went 1-4 both straight-up and ATS. Although the Rams are undefeated, they haven't done as well covering the spread. The Rams are just 3-2 ATS on the season.

Jaguars (3-2) at Cowboys (2-3)

Opening line: Jaguars, -2 points

If there's one time you should almost never bet the Cowboys, it's when they're a home underdog. The last 10 times that's happened, the Cowboys have gone 3-7 straight-up and 3-6-1 ATS. On the other hand, the Cowboys might be a smart bet here and that's because the Jaguars seem to forget how to play football against NFC teams. Since the beginning of the 2013 season, the Jags have gone 4-16 both straight-up and ATS against NFC teams. If you're thinking that the Jags were horrible from 2013 thru 2016, so we shouldn't count those games, it's not like they've been any better recently. Since the beginning of last season, they've gone 2-3 both straight-up and ATS against the NFC. That total includes a 20-15 win over the Giants in Week 1 where they covered as a 2.5-point favorite.

Ravens (3-2) at Titans (3-2)

Opening line: Ravens, -2 points

The Titans are a home underdog in this game, which is notable, because the Titans seem to thrive as a home underdog. Since November 2016, the Titans have gone 3-1 straight-up as a home dog and 4-0 ATS. That total includes two games THIS year where they covered as a home dog. In Week 2, the Titans beat the Texans 20-17 as a 3.5-point home underdog. In Week 4, the Titans beat the Eagles 26-23 as a 3-point home dog. Overall, the Titans have covered in eight of their past 10 home games. One other notable thing about the Titans is that they almost always cover after a loss. Since the beginning of the 2016 season, they've gone 12-3 ATS following a loss, which is the second best mark in the NFL over that span. As for the Ravens, Baltimore has gone just 7-13 in their past 20 road games overall, which includes a mark of 10-9-1 ATS.

Chiefs (5-0) at Patriots (3-2)

Opening line: Patriots, -3.5 points

The Chiefs are the only team in the NFL this year that's still unbeaten ATS (5-0). Not to mention, they thrive as an underdog. Since the beginning of the 2016 season, the Chiefs have gone 7-2 both straight-up and ATS as an underdog. The Chiefs are also 9-1 both straight-up and ATS in their past 10 primetime games. If there's a reason to bet the Patriots, it's because this is a primetime game in New England. In their past 10 home primetime games, the Patriots have gone 8-2 straight-up and 6-2-2 ATS (Of course, one of those two losses came to the Chiefs, so maybe betting the Patriots isn't a great idea).

49ers (1-4) at Packers (2-2-1), Monday

Opening line: Packers, -7.5 points

When the 49ers are a big underdog, you can basically count on them to lose. In their past 15 games where they were an underdog of seven or more points, the 49ers have gone 0-15 straight-up. However, they have done a slightly better job of covering the spread, going 7-8 ATS. One thing the 49ers are good at is covering the spread on "Monday Night Football." Over the past 10 years, the 49ers have gone 10-2 straight-up on MNF and an even more impressive 11-1 ATS. Of course, San Francisco is 1-4 ATS this season, which is tied for the second worst mark in the NFL, so maybe betting on them isn't such a great idea. Surprisingly, this game will mark Aaron Rodgers' first Monday night appearance since 2016. The Packers quarterback is 5-0 all-time at home on Monday night as a starter (4-1 ATS) when he plays more than one quarter in the game.

BYES: Saints, Lions