Touchdown passes are flying past NFL defenders in record numbers.
The pace slowed some in Week 5, but the 272 scoring strikes in 77 games through Sunday are 25 more than any season since the NFL expanded to 32 teams in 2002. The figure is up by 39 over last season.
Theories abound as to why. The latest rules changes favoring offenses have to help. Enterprising play designs from Sean McVay, Andy Reid and other offensive maestros are part of the equation. While there could be any number of factors, a simple explanation is hiding in plain sight. The guys lining up behind center are better -- and better equipped -- to this point in the 2018 season relative to the first five weeks of 2017.
Andrew Luck is back. In a roundabout way, Patrick Mahomes has replaced Trevor Siemian, in the respect that Mahomes replaced Alex Smith, who replaced Kirk Cousins, who replaced Case Keenum, who replaced Siemian, who became Cousins' backup. Siemian, Jacoby Brissett, Jay Cutler, Mike Glennon, Brian Hoyer and DeShone Kizer were starters one year ago. Not now.
Five weeks into the 2018 season, let's look at where all the extra touchdown passes are coming from, starting with the teams that are farthest ahead of their 2017 pace. We consider which increases appear sustainable -- and which teams might actually improve from here.
The 2018 Quarterback Tiers survey gave an early indication that the quality of quarterback play could be on the rise. The quarterbacks included in the survey graded out higher than their 2017 predecessors among 50 coaches and personnel evaluators polled (the average improved from 2.89 last year to 2.70 on the five-tier scale, with Tier 1 being the best). That was the case even though some evaluators who loved Mahomes placed him in the fourth tier as a matter of course, because Mahomes had not started enough games to be evaluated.
Indianapolis Colts
Passing TD differential: +10
The big change is having Andrew Luck back in the lineup. Luck should continue to outperform 2017 starter Brissett. He's on pace for 38 touchdown passes, two fewer than the career mark he set in 2014, his last healthy season.
Cincinnati Bengals
Passing TD differential: +5
The Bengals' number includes four touchdowns from a personnel group featuring Tyler Eifert and John Ross, who were not big contributors in 2017 (they played just five snaps together). Eifert is now out for the season. Running back Joe Mixon has had some injury issues. Andy Dalton has never exceeded 33 touchdown passes in a season. His current 38-touchdown pace will be difficult to maintain.
San Francisco 49ers
Passing TD differential: +5
This increase is due to Jimmy Garoppolo and C.J. Beathard playing instead of Brian Hoyer. Losing Garoppolo to season-ending ACL surgery will make it tougher for the 49ers to stay on pace for 29 touchdown passes, especially with so many other key offensive players suffering injuries. The injury is also a reminder that every starter is vulnerable, and backups could be making their way into the lineup as the season progresses.
Tampa Bay Buccaneers
Passing TD differential: +5
Ryan Fitzpatrick became the first player in NFL history to pass for 400 yards in three successive games. That is obviously not sustainable, whether it's Fitzpatrick or Jameis Winston in the lineup. The Bucs are on pace for 48 touchdown passes, which would match Dan Marino's former league record. Not happening.
Los Angeles Rams
Passing TD differential: +5
ESPN's efficiency metric, dating back to 2006, shows the current Rams and the undefeated 2007 Patriots as the only teams to reach the 80th percentile for offensive performance in each of their first four games. After putting up 33 points and 468 yards in Seattle on Sunday, the Rams are now the only team since 2006 to make it five games to start a season. While there's still a chance Jared Goff will maintain his 38-touchdown pace, the injuries Los Angeles suffered during its 33-31 victory at Seattle served as a reminder that talent, not just offensive design, is a huge part of the equation for any team. If the injuries pile up for the Rams, who have older players on their stellar offensive line, Goff's pace figures to suffer.
Pittsburgh Steelers
Passing TD differential: +5
Ben Roethlisberger is on pace for 35 scoring passes. That seems well within reach given his ability and the talent around him, but Roethlisberger has never thrown more than 32 touchdown passes in a season. He has missed seven games over the past three seasons, so durability is also a factor.
Miami Dolphins
Passing TD differential: +5
Ryan Tannehill's return to the lineup, replacing Cutler, has been the story. Tannehill is on pace for 32 touchdown passes, which would exceed his career high by five. It's tough to envision that happening, especially after Tannehill committed two brutal turnovers at Cincinnati on Sunday. Durability is another concern.
Atlanta Falcons
Passing TD differential: +5
This is the second season with Steve Sarkisian as offensive coordinator. The Falcons, though surprisingly inept on offense during their 41-17 defeat at Pittsburgh, appear to have fixed their red zone problems. Matt Ryan is on pace for 35 touchdown passes. He threw 38 of them during his 2016 MVP season and 32 in 2012, but typically he's in the upper 20s over a full season.
Los Angeles Chargers
Passing TD differential: +4
Philip Rivers' 13 touchdown passes match the five-game career high he set in 2013, but if he stays on his current pace and throws for 42 of them, he will set a career high by eight. That seems unlikely. Note also that Rivers has faced questionable defenses in games against Kansas City, Buffalo, San Francisco and Oakland. Tougher defenses await in the future, starting with Cleveland's in Week 6.
Chicago Bears
Passing TD differential: +4
Matt Nagy replaced John Fox as head coach, and the team also added some expensive offensive pieces in free agency. Mitch Trubisky's six-touchdown game against Tampa Bay accounts for all the improvement from the Bears' four-game pace with Glennon in the lineup last season. While it could be unlikely for Trubisky to stay on his current pace for 32 touchdown passes, he needs only eight the rest of the way to surpass his total from Weeks 5-17 last season.
Minnesota Vikings
Passing TD differential: +4
How good was Cousins in Minnesota's 23-21 victory at Philadelphia on Sunday? Good enough for head coach Mike Zimmer to heap praise on his quarterback, which Zimmer was conspicuously reluctant to do when Keenum played well last season. Cousins is on pace for 5,400 yards, with 35 touchdowns and six interceptions -- those are MVP-caliber numbers. He needs 19 touchdown passes over the final 11 games for Minnesota to pass its 2017 total.
Kansas City Chiefs
Passing TD differential: +3
Last season, Alex Smith had 11 touchdowns passes with zero interceptions for the Chiefs during their 5-0 start. Mahomes has 14 with two picks after a rough statistical game -- no passing touchdowns, two interceptions -- during a victory over Jacksonville. Mahomes is on pace for 45 scoring passes. That seems unrealistic, but he needs only 13 more to surpass Smith's total for last season.
Baltimore Ravens
Passing TD differential: +3
Joe Flacco went without a scoring pass in the Ravens' overtime defeat at Cleveland, but the Baltimore passing game has been sharper overall thanks to a better set of pass-catchers for the veteran. Flacco is on pace for 26 scoring passes, which would be one shy of his career high, set in 2014.
New York Jets
Passing TD differential: +2
The Jets are on the positive side of the ledger thanks in large part to the three touchdowns rookie Sam Darnold tossed against Denver in Week 5. Darnold is on pace for 22 scoring passes, which could be on the high side. Russell Wilson (26), Luck (23), Dak Prescott (23) and Winston (22) are the only rookies to throw for that many over the past decade. Cam Newton (21), Derek Carr (21), Dalton (20) and Robert Griffin III (20) came close.
Carolina Panthers
Passing TD differential: +2
Newton has seven, putting him on pace for 28. He had 35 during his 2015 MVP season, but he has otherwise been in the 19-24 range for his career. Newton does still have two games against the Saints, two against the Buccaneers, one against the Falcons and one against the Lions. Those defenses could be leaky enough to help Newton maintain his current pace under new coordinator Norv Turner.
Seattle Seahawks
Passing TD differential: +2
Wilson's three scoring passes against the Rams put him on pace for 32. It looks like the Seattle ground game is back, which should make the passing game harder to defend. Seattle has been more proficient at hitting for long touchdown passes, which takes away scoring chances for the running backs near the goal line.
Jacksonville Jaguars
Passing TD differential: +1
Blake Bortles' one-score, four-pick game at Kansas City will stop any lingering talk about increasingly efficient play from him.
Detroit Lions
Passing TD differential: +1
Matthew Stafford has 10 of them so far. That puts him on pace for 32, three more than he had last season. That seems reasonable. Stafford set a career high with 41 in 2011. He exceeded 30 one other time, with 32 in 2015.
New England Patriots
Passing TD differential: +1
Tom Brady has 12, which projects to 38 for the full season. Brady hasn't had that many since reaching 39 in 2011, but he has been in the 32-36 range in each of his past three full seasons, and he had 28 in 2016, when he missed the first four games. Julian Edelman's return should provide the needed boost.
Tennessee Titans
Passing TD differential: 0
Marcus Mariota has been beat up, and his receivers didn't do him any favors at Buffalo. The smart money says Tennessee, with only four scoring passes in five games, should improve upon its current abysmal pace, which projects to 13 scoring passes for the season. Of course, the Titans had only 14 last season.
Cleveland Browns
Passing TD differential: -1
The Browns had six at this point last season and threw 15 for the full year. They have five so far and will seemingly pick up the pace if Baker Mayfield outperforms Kizer, the 2017 starter.
Oakland Raiders
Passing TD differential: -1
For all his struggles, Derek Carr has the same number of scoring passes as he had through five games last season (E.J. Manuel also had one at this point in 2017, putting the Raiders one off their previous pace).
Washington Redskins
Passing TD differential: -2
The Redskins have played only three games heading into Monday night, so I'm using their 2017 three-game total as the comparison. That is not much to go on.
New York Giants
Passing TD differential: -2
Eli Manning tossed a couple of scoring passes Sunday, but with six for the season, he is on pace for 19, which would match the total he set in 15 games last season. Manning tossed fewer than 19 over a full season just once, when he had 18 with 27 picks in 2013. All bets are off.
Arizona Cardinals
Passing TD differential: -2
Josh Rosen completed 10 of 25 passes for 170 yards and one score against a 49ers defense that had surrendered 11 touchdowns and 265 yards per game to Mahomes, Cousins, Rivers and Stafford over the first four weeks.
New Orleans Saints
Passing TD differential: -2
Drew Brees is on pace for 32 touchdowns. He matched or exceeded that total in nine consecutive seasons before tossing only 23 as part of a balanced offense in 2017. It won't be a shock if he gets back into the 30s this season.
Denver Broncos
Passing TD differential: -3
This is a surprise, but because Denver tossed only 11 scoring passes after the fifth game last season, there's a decent chance the Broncos will improve upon their 2017 total with Keenum behind center instead of Siemian, Brock Osweiler and Paxton Lynch.
Green Bay Packers
Passing TD differential: -3
The Packers lost Aaron Rodgers in the sixth game last season and then threw only 12 scoring passes over the final 11 games. Rodgers has in recent seasons tossed between 18 and 30 scoring passes over the same period.
Buffalo Bills
Passing TD differential: -4
Buffalo ranked 21st in the league with six scoring passes through five games last season. They have only two so far, which is the fewest for an NFL team through five games since the 2009 Raiders had only one. It's the fewest for the Bills since 2007. The 2017 Bills tossed 10 in their final 11 games.
Philadelphia Eagles
Passing TD differential: -4
Philly led the NFL with 28 touchdown passes over its final 11 games last season. That sets a high bar for Carson Wentz, who has five touchdowns in his first three games back in the lineup this season.
Houston Texans
Passing TD differential: -4
The Texans had 12 scoring passes through five games last season, one off the Packers' league-leading total in that span. Watson's current pace has him on track for 26 scoring passes. That seems reasonable as he gains strength in his return from last season's ACL injury.
Dallas Cowboys
Passing TD differential: -6
This was a tumultuous summer for Dallas, as Jason Witten retired, Dez Bryant was released and the offensive line lost Travis Frederick. This is a one-dimensional team, and that one dimension is not throwing touchdown passes. Dak Prescott is on pace for only 16 of those, which would match the Cowboys' total for 2015, the year before Prescott arrived. The team hasn't had fewer in a season since 2002, when Chad Hutchinson and Quincy Carter finished with seven scoring passes apiece.