Hype Trap Bet: Is this the year of the backup QB?

The date was Sept. 30, 2001. The Seattle Mariners won their 111th game -- en route to tying the MLB record for wins in a season. The first iPod was 23 days away from being released. The first movie in the Harry Potter and Lord of the Rings series would come out later that year.

And a young, California kid named Tom Brady stepped onto an NFL field as a starting quarterback for the very first time.

The New England Patriots were massive 12.5-point home underdogs against the Peyton Manning-led Indianapolis Colts, went on to win 44-13 on the back of two interceptions returned for touchdowns, and the rest, as we know, is history.

No, you're not having déjà vu. This is exactly the intro to my piece from two weeks ago about the Patriots.

So why bring this up again? Because there's yet another lesson to be learned from that day about betting against the unknowns of backup quarterbacks.

This season has been brutal with quarterback injuries, with the last few weeks being especially problematic. Between players out for the season, playing through injuries, or getting knocked out of games and are uncertain for Week 9, nearly half the league has been forced to scramble under center this year, and the season isn't even halfway over.

That list also doesn't include the 49ers, who were expecting Brock Purdy to miss a game with concussion symptoms last week, or Joe Burrow or Derek Carr, who both played through injuries for the better part of a month and their performance notably suffered.

With the likes of Taylor Heinicke, Aidan O'Connell, Brett Rypien, Jaren Hall, Tyson Bagent and Clayton Tune potentially calling the shots this week, it's gotta be easy to bet against the backup quarterbacks, right? Right? (Cue the Anakin-Padme meme)

Not so fast, my young Padawan.

We can all agree that quarterback is the most important position on the football field, and it's on the short list for most important position in all of sports. But how much does a line really move for a starting quarterback injury?

This question has been asked to oddsmakers many times in the last few years, including by folks here at ESPN -- notably here and here

USA Today ran a similar straw poll ahead of this season. They all came to the same conclusion: the elite QBs are worth about a touchdown, the middle of the pack QBs are worth about a field goal, and some of the low-end starters may be on par with their backups.

When Brock Purdy was placed in concussion protocol last week and Sam Darnold was looking like the starter, the line moved from SF -5.5 to SF -3.5. Two points, not even including a key number, for a player who was the third favorite to win MVP at +550 just a few weeks ago.

Unless you're doing this professionally or have been betting for a while, you might not be able to cap games by yourself (I suggest trying to do this sometime though - try guessing the spread for every game one week and see how close you get to the sportsbook lines). You might have a slight lean on a game or two, but if your projection is off from the market by more than 2-3 points, you're probably missing something.

The same thing can happen when accounting for backup QBs. The line may move a point or two, but if you're not tracking it, you might feel like the line isn't factoring in the QB enough. Get enough people to buy into the same narrative and move the line, and you're left with a chance to bet against the public.

Here are some of the consensus opening lines for Week 9 games prior to the QB uncertainty, and what the line is currently using ESPN BET odds.

Just based on some rough math, it looks like Kirk Cousins is worth 4 points, and Taylor Heinicke is considered 1 point better than Desmond Ridder. Matthew Stafford accounts for 4.5 points to the spread, Justin Fields 2 and Jimmy Garoppolo a single point.

Here's where the math comes in.

Looking at the season as a whole, we've seen 30 games started by backup QBs, with those QBs going a combined 14-13-3 against the spread. However, the narrative comes into play when the backup is making their first start with the team. In that scenario, we've seen those underdogs cover 6 of 9 games, with 4 outright wins.

Betting all these teams on the moneyline would put you up 4.15 units on just 9 bets. It's a small sample, but this is certainly not a trend I'd want to blindly ignore.

In Week 9, there are a few spots where you could look to attack this exact trend against the sportsbook line movement.

I'll just add one final note: ESPN Analytics currently has the Rams and Vikings favored to win their games, resulting in significant moneyline value as well.

Miami Dolphins at Kansas City Chiefs (-2, 50.5)
Sunday 9:30 a.m. ET, Frankfurt Stadium, Frankfurt, Germany

The game of the year, again! How lucky are we to have so many games of the year already, and it's only Week 9.

I'm not betting a side in this game. Dolphins backers will point to Mahomes' recent struggles and the Chiefs easy schedule (last 6 opponents have had a combined 21-27 record). Chiefs backers will note that Miami has lost both its games against real competition (Bills, Eagles), also beating up on bad teams.

I also don't want to bet on the total, although I would lean under (4 of 8 Dolphins games have gone under this total, and the Chiefs haven't had a game top 51 points all season). Instead, I'll look to the prop market.

Travis Kelce over 78.5 receiving yards (-118) and longest reception over 21.5 yards (-122)

The Dolphins rank bottom-5 in receptions and yards allowed to tight ends this season. They've allowed a TE reception of 20-plus yards in four different games, including to both elite tight ends they've faced (Darren Waller, Dallas Goedert), and Kelce has four catches of 20-plus yards in seven games. Miami has allowed the 3rd-most YAC to tight ends this season, and Kelce has the second-most YAC of any tight end.

Especially coming off a bad loss to the Broncos, I expect Kansas City to come out peppering No. 87 with as many targets as he can handle, and we only need one broken play to get there.

Jason Sanders under 6.5 kicking points (-122)

To lose this bet, Sanders has to do one of the following:

Mike McDaniel is an aggressive head coach that trusts his offense. They're scored 35 touchdowns and attempted only 9 field goals all season (the fewest in the entire league). Three of those 9 field goals came in the final 30 seconds of the first half.

Sanders hasn't made multiple FG in a game since Week 1 and hasn't even attempted multiple FG since Week 2. I'll take my chances on McDaniel relying on Tua Tagovailoa and Tyreek Hill to deliver -- and there's even some upside of 2-point conversions and missed kicks on a completely unknown turf in Germany.