Taylor toiled as Flacco's backup for four seasons before taking over the reins as Buffalo's starting quarterback last season. Meanwhile, Flacco struggled at times last year before suffering a season-ending knee injury during the Ravens' worst campaign (5-11) in eight years.
Point spread: Ravens opened as three-point favorites; the total was 43.5 early in the week, according to sportsbooks monitored by Odds Shark. (Line updates and matchup report)
NFL pick, via Odds Shark computer: 23.3-16.4 Ravens (NFL picks on every game)
Why the Bills can cover the spread
Last season the 8-8 Bills extended their current playoff drought to 16 years, the longest in North American team sports. Buffalo finished strong, covering in straight-up wins over Dallas and the New York Jets, while showing flashes of the club's defense that was so dominant in 2014.
The Bills are expected to use a simplified defense and aggressive pass rush and spend the afternoon pressuring Flacco, who looked healthy in a brief preseason appearance.
Freshly signed to a big contract extension, Taylor will aiming to prove that the Ravens made the wrong decision by letting him escape to Buffalo.
Taylor will enjoy multiple offensive options with the return of wide receiver Sammy Watkins from offseason surgery, while rusher LeSean McCoy demonstrated his versatility with four catches for 58 yards and a touchdown in Buffalo's 21-0 preseason win over the Giants.
Why the Ravens can cover the spread
The Ravens were ravaged by injuries in 2015, finishing with a 5-11 SU record including a 1-4 SU run following the loss of Flacco. But with the return of multiple starters from stints in the clinic, Baltimore looks poised for a rebound.
Baltimore went undefeated SU and against the spread in preseason action, holding opponents to just 15 points per game. That bodes well against a Bills squad that struggled to score points in August, averaging just 13.75 points per game, including a blowout 31-0 loss in Detroit in their preseason finale.
The Ravens have also claimed SU wins in the Bills' past three visits to Maryland, but remain haunted by their current three-game SU losing streak in Week 1 matchups.
The Ravens kick off the regular season riding high following a successful August, but questions remain about how much rust remains with so many veterans returning to action from recent injury.
Buffalo must contend with a lack of depth, particularly on offense. But the youthful Bills have covered in their past three against Baltimore, and take a boatload of motivation into a Week 1 matchup in which they should cover as slim road underdogs.
The total has gone under in five of the Bills' last six games against the Ravens.
The Ravens are 0-10-2 ATS in their last 12 games as a favorite.
The Bills are 9-2 ATS in their last 11 games in Week 1.
All NFL betting lines and point spreads data courtesy of Bleacher Report’s official odds partner Odds Shark. All quotes gathered firsthand unless otherwise noted. Check out Twitter for injury and line movement updates and Odds Shark YouTube for picks and analysis, or download the free odds tracker app.