The NFL season is at the halfway mark, which means it’s all too tempting to take the first half’s results and extrapolate them to try and project what the full season will look like. Your team is 5-3? That means they’ll be 10-6. Your quarterback has thrown 2,200 yards? Then he should wind up right around 4,400. You get the idea.

Of course, we all know it doesn’t work that way. Eight—or for some teams, seven—games is a small sample size, and first-half trends don’t always become second-half results. At this time last year, Todd Gurley was in sight of the single-season total touchdown record, Patrick Mahomes was close to the pace needed to set the passing touchdown record, Matt Ryan looked like a contender for the season-long passing yards belt, Kirk Cousins seemed like he could set a new mark for single-season completions, Adam Thielen was hauling in receptions like few before him, and Julio Jones was getting all kinds of yards. None of those early-season performances turned into new records. But that doesn’t mean it couldn’t happen this season. With that in mind, here are the seven single-season records that look vulnerable in 2019:

Adjusted Net Yards Per Pass Attempt

Current record holder: Peyton Manning (9.78, 2004)

2019 contender: Patrick Mahomes (9.51)

Adjusted net yards per attempt is my favorite rudimentary quarterback efficiency stat. It’s not the be-all, end-all for QB evaluation (then again, what is?), but it gives you a better general overview than passer rating. The stat takes basic yards per attempt—not a bad stat, despite what Troy Aikman may say—and folds in sacks, interceptions, and touchdowns. Passer rating, on the other hand, ignores sacks, which is unfortunate because there is ample evidence that many sacks are the result of a QB holding onto the ball too long. Passer rating is also oddly capped at 158.3. ANY/A has no limit, which makes sense—there is always room to push quarterback efficiency to new levels.

A look at the single-season ANY/A leaderboard mostly matches up with the eye test. Peyton Manning set the all-time mark in his 2004 MVP season; Aaron Rodgers’s 2011 run (when he set the all-time mark in single-season passer rating) is second; Nick Foles’s 2013 campaign (a shockingly good run) is third; Matt Ryan’s MVP season in 2016 is fourth; Dan Marino’s record-shattering 1984 (arguably the greatest passing season ever if you adjust for era) is fifth. Mahomes is in sixth place for the mark he recorded last season.

Even before an ankle injury sapped much of his playmaking abilities and a knee injury sidelined him for Week 8’s game against the Packers, Mahomes hasn’t looked quite as special this season as he did in 2018. His touchdown rate has fallen from “oh my god” levels (8.6 percent) to a still very good mark (6.2). And after beginning 2018 on a 9-1 tear, the Chiefs dropped two of their first six games this season. But that doesn’t mean Mahomes as a whole has regressed. In fact, he’s gotten better.

While the big touchdown bombs haven’t always been there in 2019, the reigning MVP has taken a scalpel to the parts of his game that held him back last season. His sack rate is down from 4.3 percent to 3.2 (the lowest figure in the league). His interception rate went from 2.1 percent to 0.4 (also a league low). And his yards per attempt have increased from 8.8 to 9.0. The excitement factor may have lessened some this year, but Mahomes has become a more efficient, lethal quarterback on the whole. His overall ANY/A stands at 9.51, which would be the second-highest single-season number ever, just 0.27 off of Manning’s record.

Mahomes is already practicing again, though the Chiefs say they’ll be cautious with his return. And if he hopes to pass Manning, he’ll have to come back and up his already incredible level of play. But 2019 has made it clear that Mahomes has the ability to stretch the boundaries of what seems possible for other quarterbacks, as well as himself.

Scrimmage Yards

Current record holder: Chris Johnson (2,509, 2009)

2019 contender: Christian McCaffrey (1,078, on pace for 2,464)

In a league where the perceived value of running backs is shrinking, Christian McCaffrey is generating real MVP buzz. It would take a lot for him to become the first back to be named MVP since Adrian Peterson in 2012, but he is already cementing his place as the best all-around playmaker in the NFL.

It’s hard to overstate McCaffrey’s importance to the Panthers offense. Carolina has racked up just 2,348 yards on the season, meaning McCaffrey—who accounts for 1,078 of those—is contributing more than 45 percent of the team’s yards from scrimmage. For comparison’s sake, Dalvin Cook has 1,116 scrimmage yards (he’s played in one more game than McCaffrey), which is an incredible number … but accounts for only 35 percent of the Vikings’ yards. McCaffrey has also been on the field for 93.6 percent of the Panthers’ offensive snaps, which would be a career high for him. No nonquarterback has done more for his team than McCaffrey has for the Panthers.

Whether McCaffrey can keep this pace up over the next nine games is still a massive question mark. Historically, only eight players have ever put up more scrimmage yards through seven games than CMC has this year. Interestingly, that list doesn’t include Chris Johnson’s 2009 season, when he set the current record—his scrimmage yards through his team’s first seven games that year are tied for 50th all time. Johnson exploded in the back half of that year, which is a good indication of just how long we have left to go. McCaffrey may be on pace to flirt with the record, but he isn’t even halfway through his season yet.

Rush Yards by a QB

Current record holder: Michael Vick (1,039, 2006)

2019 contender: Lamar Jackson (576, on pace for 1,316)

It’s time to start talking about Jackson as the greatest rushing quarterback ever. Lamar is averaging 82.3 rushing yards per game, which is ninth most in the league for any position. He’s on pace to smash Vick’s QB rushing record from 2006 by over 250 yards—and that’s including his Week 1 performance against Miami when he tallied just 6 rushing yards. He’s exploded on the ground since that game, though, and has eclipsed 100 yards rushing in three games.

Crucially, Jackson is thriving as a passer, too. Whereas Vick in 2006 needed to run to supplement his mediocre passing line (52.6 completion rate, 6.4 yards per attempt, 20 touchdowns to 13 interceptions), Jackson has done damage through the air as well. He’s completing 63.3 percent of his passes (averaging 7.7 per attempt) and has 11 touchdowns to five interceptions.

My favorite play of Jackson’s season, though, is a relatively mundane 5-yard gain he had against the Chiefs in Week 3:

.@lj_era8 had him going the wrong way after that juke



: #BALvsKC -- CBS

: NFL app // Yahoo Sports app

Watch on mobile: https://t.co/qnNxI5gZ8j pic.twitter.com/B9SElB3a5T — NFL (@NFL) September 22, 2019

Much has been said about Jackson’s speed, and it’s true: On any given play, he can be the fastest player on the field. But his ability to stop on a dime is just as noteworthy. It’s the 60-to-zero-and-back-again ability that allows Jackson to run roughshod over defenses—and also prevents him from taking too many big hits. Barring injury, Jackson will almost surely take the running QB crown.

Passing Completion Percentage

Current record holder: Drew Brees (74.4 percent, 2018)

2019 contenders: Drew Brees (75.8 percent), Derek Carr, and Kirk Cousins (both at 72.1 percent)

Brees has four of the top six seasons ever by completion percentage, and last year he crushed his own record (set in 2017) by 2.4 percentage points. He’s already topping that mark this year, connecting on a whopping 75.8 percent of his throws. Of course, that’s on a sample size of just 91 passes, and Brees will need to get to 224 attempts to qualify for Pro-Football-Reference’s leaderboard. But barring another injury setback, that shouldn’t be a problem.

Brees’s completion percentage has steadily risen in each of the last three seasons, not including 2019. That is in part because Brees has quietly become one of the least aggressive passers in football. Per Pro Football Focus, Brees has gone deep (more than 20 yards downfield) on just 5.5 percent of his throws this season, which is the lowest mark of any quarterback who has attempted at least 75 passes. Brees’s average depth of target this season, per Pro-Football-Reference, is 6.3 yards, which would be the second-lowest mark of any QB this season if Brees qualified for that leaderboard. His passing chart from Week 8 does a good job of illustrating just how many of his throws are coming on simple dump offs near or behind the line of scrimmage:

This isn’t all Brees’s fault—Sean Payton’s offense is a big contributor to this shift. The only quarterback behind Brees in average depth of target this season is Teddy Bridgewater, who took over for Brees while he was out with a thumb injury. Even factoring that in, though, Bridgewater completed just 67.7 percent of his passes—Brees is still the best at what he does.

Beyond Brees, Kirk Cousins and Derek Carr could also contend for the completion percentage crown, though they’d each need to boost their numbers a bit to get there. Cousins has been on a hot streak as of late, working his way into the fringes of the MVP conversation. But Cousins’s high completion percentage feels less sustainable than Carr’s. Cousins has an average depth of target of 8.2 yards, while Carr’s is just 6.8. Similarly, Next Gen Stats estimates that Cousins’s expected completion percentage—based on the difficulty of his throws—is 63.9 percent. Cousins is exceeding that number by over 8 percentage points, indicating that he should regress to the mean some. Carr’s expected completion percentage is at 69.3 percent, the second-highest mark in the league, which means Carr is overachieving at a more manageable (and sustainable) rate than Cousins.

Receptions

Current record holder: Marvin Harrison (143, 2002)

2019 contender: Michael Thomas (73, on pace for 146)

Thomas has been the most productive wide receiver in football this season, leading the league in receptions and yards (875) to go with four touchdowns. The fourth-year pro already has 89 targets this year, and he’ll most likely fly by his previous career high of 149, set in 2017. The Saints made Thomas the highest-paid wideout in football this offseason, and all indications point to that money being well spent.

But Thomas’s chances of breaking the single-season reception record have more to do with the person throwing him the football than his own performance. With Bridgewater under center, the Saints leaned more heavily on their star wideout to carry the load on offense. Now that Brees is back in the fold after missing five weeks, it may stand to reason that the Saints would spread the ball around more evenly. But initially it seems that won’t be the case—in fact it may even be the opposite. In the five games Bridgewater started, Thomas averaged 10.4 targets and 8.4 receptions. In the two full games Brees has played, he’s averaged 12 targets and 10.5 receptions. These are extremely small sample sizes, but they show just how much of the Saints offense runs through their star receiver.

Field Goals Made

Current record holder: David Akers (44, 2011)

2019 contenders: Zane Gonzalez and Josh Lambo (both at 21, on pace for 42)

Neither Gonzalez nor Lambo are coming for Justin Tucker’s crown as the best kicker in football. Their field goal numbers are more a product of the offenses they serve rather than their own kicking prowess. Both have benefited from a phenomenal number of short- and intermediate-range kicks this season: Gonzalez has attempted 18 kicks of 39 yards or less (the most in the league), while Lambo has booted 16 kicks from that distance (second most). Gonzalez has taken just one kick of 50-plus yards, while Lambo has attempted zero. Those are a shockingly low numbers—14 kickers have attempted at least three kicks of 50 or more yards this season.

Gonzalez and Lambo are each on pace to fall just two made field goals short of Akers’s record. But since neither have shown themselves to be particularly good at kicking from deep, their best chance at catching Akers is for their respective offenses to keep stalling out in the red zone.

The Cardinals have scored touchdowns on a league-low 32.1 percent of their red zone possessions this season. Arizona coach Kliff Kingsbury has already shown himself to be incredibly conservative with fourth downs in the opposing team’s territory, and the Cardinals are dealing with a number of injuries to their running backs, which could limit their ability to punch the ball through in short yardage situations. Basically, Gonzalez should continue to have plenty of opportunities to crank out chip-shot field goals. For the Jaguars, it’s a little trickier. They’re converting on just 35.7 percent on their red zone chances, which is third worst in the league. Leonard Fournette has just one rushing touchdown this year despite seeing 17 attempts from inside the 10. Fournette is tied for second among running backs (with at least 100 snaps) in yards after contact per rush, per PFF, so it’s likely he’ll improve on that TD figure down the stretch. If that happens, it could mean fewer field goals for Lambo.

Pick Sixes

Current record holders: Eric Allen (1993), Ken Houston (1971), and Jim Kearney (1972) (all with four)

2019 contender: Marcus Peters (two, on pace for four)

There is no one player better at jumping routes than Marcus Peters. While Peters’s aggressive tendencies sometimes result in botched coverages, they also can create the elusive big plays that defenses need to swing games. Since he entered the league in 2015, Peters leads the NFL in interceptions (25), pick sixes (five), and defensive scores (six). No current NFL player would be a more appropriate holder of the pick-six record.

That said, while Peters is technically on pace to match the record, he still has a long way to go. He needs three more to break the record, the equivalent of the number of pick sixes he had in his previous four seasons combined. The Ram turned Raven is the best ballhawk in the league, but pick sixes are so rare that getting this record is mostly about luck.