At this stage of the postseason, NFL betting tends to be pretty cut and dry. So, it came as no surprise last Sunday night when Kansas City opened as -2.5 favorites to win the AFC championship over the Bengals. Some movement could be expected from that initial number, of course, but it was surprising to see a five-point swing in favor of the Bengals by early Tuesday. The line has since dipped to KC +1, but still — what?
MORE BENGALS-CHIEFS:
Betting preview | Best props | SGP | DK lineup | FD lineup
The Andy Reid-led Chiefs have perennially served as the class of the AFC, winning seven straight AFC West titles, making the conference championship in each of the past four postseasons, and going one-of-two in Super Bowls. Patrick Mahomes, whose awards collection includes a Super Bowl MVP, league MVP, two All-Pro selections, and five Pro Bowls, has a 9-3 lifetime playoff record. He's also coming off arguably the most impressive regular season of his career, posting an NFL-leading 5,250-yard and 41-TD campaign that has him as an overwhelming -750 favorite to win his second league MVP.
Mahomes' legacy speaks for itself, but does the sudden five-point odds shift this week suggest that sportsbooks believe Joe Burrow has already overtaken Mahomes as the best quarterback in the NFL, or are other factors at play with this surprising shift?
MORE CONFERENCE CHAMPIONSHIP: Odds, lines, spreads | Bill Bender's Best Bets
Let's dive deeper into this discussion, looking at all the potential factors that went into sportsbooks changing the Chiefs from a -2.5 favorite to a +2.5 underdog.
SUPER BOWL STORYLINES: Ranking every possible SB 57 matchup | Power Rankings
Why are the Bengals favorites against the Chiefs in the AFC championship game?
Oddsmakers don't usually disclose their secrets, but if you gave all the oddsmakers of the American betting scene truth serum, they would likely explain that countless factors go into every spread. Everything from talent, matchup, depth, coaching, health, weather, betting trends, and even public perception can impact the ebbs and flows of a matchup's spread.
In many ways, an opening spread is like an advance weather forecast (and we all know how drastically those can change the closer we get to the actual day), but a five-point swing in under 48 hours still seems a bit drastic. What happened to the infamous home-field advantage at Arrowhead? The Chiefs have been 'dogs in one home playoff game since 1991, and Mahomes has never been a postseason underdog in his professional QB life. Hell, before Josh Allen and the Bills rolled into GEHA Field in Week 6 of this season, Mahomes had never been a home underdog in his entire five-year career as a starter. How can this be explained?
1. Patrick Mahomes' Injury: High-ankle sprain = low-hanging fruit
The most glaringly obvious reason for the initial line movement was the ankle injury Mahomes sustained in the divisional-round win over the Jags. Nobody could dispute that. The injury itself was a live-action drama unfolding in front of our eyes. Mahomes was down. Then he got up and hopped off the field, not putting weight on the right ankle. He went back in after a timeout and played a few snaps before eventually heading for the locker room, with Chiefs fans everywhere likely suffering from a collective anxiety attack.
X-rays taken during the game revealed the damage was not severe enough to keep him off the field in the second half. In all, Kansas City went one full offensive possession without its franchise player, a 98-yard Chad Henne drive resulting in a Travis Kelce touchdown that pleasantly surprised the Arrowhead faithful.
A field goal and a touchdown later, Mahomes helped the Chiefs cement the AFC championship berth. After Cincinnati polished off the Bills at Orchard Park the next day, the opening odds for the conference title game revealed — big surprise — that KC were home favorites. But then, a Schefty-bomb came in:
MRI today confirmed that Chiefs’ QB Patrick Mahomes suffered a high ankle sprain during Saturday’s win over the Jaguars, per league source. “Nothing more than that,” said one source, and Mahomes has said he plans to play in next Sunday’s AFC Championship Game.
— Adam Schefter (@AdamSchefter) January 22, 2023
"Nothing more than that?" Isn't a high-ankle sprain a fairly significant injury on its own? Don't most QBs miss at least two weeks with that sort of an ailment, sometimes four-to-six if they are known as mobile QBs? Heck, Mac Jones suffered a high-ankle sprain earlier in the season and he appeared as though he had taken a Forrest Gump snakebite in the Vietnam jungle!
Reid has downplayed the severity of the sprain, saying that it seems much less severe than the one Mahomes suffered in 2019. It's worth noting that Mahomes played through that one, too, and went 5-2 in the seven games after sustaining the injury. So, maybe it's nothing to worry about, which would explain the initial call to list the Chiefs the faves like always. Still, there are worries that Mahomes will be limited, perhaps significantly, by the injury.
2. Cincinnati has owned the Chiefs -- and the spread -- over the past year
Of course, for many bettors, the Mahomes injury was just the icing on the cake of an already-made decision to back Joe Burrow and the Bengals. Joey Brr must have ice in his veins because he's never met a spread he can't obliterate. The former No. 1 pick has helped Cincinnati cover 21 spreads over his past 26 starts, an unreal 80.7-percent cover rate. That includes a 13-5 ATS record this season. More impressive, he has led Cincy to an 8-2 ATS road record. Oh, and there is also the minute detail that Burrow is 3-0 against Mahomes since last January.
#Bengals players are openly calling the #Chiefs Arrowhead stadium, "Burrowhead" because of Joe Burrow's dominance over Patrick Mahomes 📝
— Dov Kleiman (@NFL_DovKleiman) January 25, 2023
Burrow is 3-0 in his career vs Mahomes pic.twitter.com/JiBvoyjSy9
Mahomes, meanwhile, has not fared as well when it comes to covering spreads. The Chiefs have gone just 6-11-1 ATS this season, including a paltry home cover rate of 2-6-1 (25-percent cover rate, third worst in the NFL). Add an ankle injury to these already sharp contrasts in cover rates, and it's easy to see why BetQL has 85 percent of sharp money and 76 percent of tickets on the Bengals.
Burrow already eliminated MVP candidate Josh Allen and the Bills at Orchard Park, where Buffalo had been 7-1 before getting tiger-punched in the mouth. Naturally, the betting public doesn't care that Kansas City has an 8-1 home record since the start of the 2022 season, and any line between -2.5 and +2.5 might as well be a pick 'em in the eyes of the oddsmakers. Home teams are typically at least -3 favorites if books truly expect them to win the game.
With most playoff games decided by a field goal or more, any odds lower than three suggest it's regarded as a pretty tight contest. Why wouldn't bettors go with the guy who has been printing money over the past four months!? The Bengals +5.5 was the overwhelming favorite bet of the divisional round, and they look poised to be the overwhelming favorite bet this week as well.
3. Oddsmakers and sportsbooks are trying to drive more betting traffic
Often, abrupt changes in odds can be attributed to sportsbooks trying to (a) drive in more traffic for the game in general, or (b) quell the traffic moving in one direction and influence traffic to the other. This week could be a classic example of "a little bit of column A, a little bit of column B."
Casual bettors might be wary of betting this game either way — the combination of injury volatility, home-field advantage, Mahomes' 9-3 playoff record, and Burrow's sizzling ATS run might have a ton of people saying "Nah, we're good." But when the everyday bettor logs in and sees the Chiefs suddenly at +2.5 (or even now, at +1) and Mahomes is no longer wearing a walking boot, they may smash-bet the home squad with the misconceived notion that they're getting value.
As seasoned bettors know, +1 yields little value. Nine of the past 10 NFL games — and 84 of the past 87 — have been decided by more than one point. You're not "taking the points" (or rather, point) — you're betting a moneyline with a bowtie shaped like a plus symbol.
Speaking of sharp bettors, changes in odds can often be methods of deterring sharps from making bets on a certain side (or at least decreasing their potential profit margins). When spreads change, the moneylines obviously change with them. Sportsbooks can lessen the blow — or limit their 'liability' — if the Bengals win on the road again by proactively adjusting their spread and in turn stripping the plus-value away from their moneyline.
When Cincy was +2.5, its moneyline was +100. When Cincy moved to -2.5, its moneyline careened up to -145. Now that Cincy is -1 — likely because that juiced-up -145 scared some bettors away from the Bengals — it's at -110. That's the same vig you'd be getting if you bet either side of the one-point spread.
We already told you that sharp bettors are all over the Bengals, with 85 percent of money on their spread since open and 72 percent on their moneyline. The books might think that they can do some damage control to protect against getting smoked again like last week in Buffalo. Such tactics might work on casual bettors, who can be easily influenced by every little shift in lines and spreads, but the majority of sharps (a) already have most of their money in or (b) will wait for the odds to shift again this weekend.
Should you bet on the Bengals or Chiefs?
In the end, you are the one doing the research and laying down your own money. Once you make up your mind on who you think will win the game, make sure your wager tells the same story you expect to unfold on the field. Even if the spread changes drastically or the value of your potential payout takes a hit, your top objective should be to win your wager.
All too often, like DFS players swapping out a player so they can spend every last dollar (as opposed to picking an optimal lineup even if money is left on the table), bettors let a sportsbook influence them by adjusting odds and instilling the age-old gambling fear that 'there's something we don't know.'
The truth is, oddsmakers are basically the sports equivalent of insurance actuaries — they constantly figure out ways to finance their operation, keep the profits driving up, and lessen the blow of liabilities taken on or money paid out. Things get a lot simpler once you start deciphering the "why" of each change to a spread, line, or over/under.
