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Tom Brady is getting old.

That's not a hot take. It's a simple fact. Brady is 41: That's creaky-back, graying-whisker old, older than all but one full-time starting quarterback (Warren Moon in 1998) in NFL history. Kale smoothies and New Age workouts can make Brady one of the healthiest, spryest 41-year-olds on the planet, but nothing can make him 31 again.

Brady's statistics are in decline.

Again, that's a fact, not a "take." He posted his highest interception total and lowest touchdown rate since 2013 this season and his fewest yards per attempt and yards per game and lowest passer rating since 2014. And it all happened in a season of record passing statistics.

The question for the Patriots as they prepare to face the Chargers on Sunday is not whether Brady has declined with age but how far he has declined.

Brady hasn't slipped to Peyton Manning 2015 or Brett Favre 2010 levels just yet. But a close look at the numbers reveals he has reached the point where the Patriots offense is built more to compensate for his weaknesses than to rely on his strengths, making Brady and the Patriots more vulnerable in the playoffs than they have been in over a decade.

Inside the Numbers

The NFL has been accumulating "Next Gen Stats" using motion-capture GPS technology for three years. Most of the data is used strictly for novelty purposes, like figuring out how fast Tyreek Hill runs for a touchdown in miles per hour (about 22.0). But the Next Gen Stats also include a trove of data about the lengths of throws, the time a quarterback spends in the pocket and so forth. The data has barely been explored, because analytics types like me have no clue what to do with most of it.

Let's examine Brady's rankings in some easy-to-understand Next Gen Stats metrics:

Time to throw calculates how many seconds elapse before the throw, per pass attempt. Brady ranks seventh in the NFL at 2.6 seconds per throw.

Completed air yards and intended air yards measure the down-the-field distance of the average pass attempt and pass completion. Brady's average attempt travels 7.6 yards downfield, which ranks 24th in the NFL. His average completion travels just 5.6 yards, which ranks 23rd.

Air yards to the sticks measures how far in front of or past the first-down marker the average pass attempt travels. Brady's AYS figure is minus-1.1: His typical throw travels to a point 1.1 yards in front of the first-down marker, which ranks 21st.

Aggressiveness measures the percent of passes thrown into tight windows, as measured by the GPS gizmos. Brady's figure is 13.9 percent, which ranks 27th.

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For a moment, let's suspend any value judgments and unpack these stats to create a snapshot of Brady's 2018 passing results.

Brady got rid of the ball faster than all but six quarterbacks this season. That makes sense: He's one of the quickest decision-makers in NFL history and isn't likely to scramble around for 10 seconds like Russell Wilson in search of an open receiver.

He consistently throws and completes shorter passes than most other starting quarterbacks. To give you an idea of what sort of company Brady kept in 2018, the two other quarterbacks who averaged 5.6 completed air yards this season were Case Keenum and Kirk Cousins.

Brady rarely threw into tight windows. The quarterbacks with aggressiveness rates in the 14 percent range included a mixed bag of Wilson, Nick Foles, C.J. Beathard, Deshaun Watson and Josh Allen.

Brady's average throw was 1.1 yards short of the sticks. There are a lot of situational factors in this figure—Andrew Luck and Carson Wentz, neither of whom would be classified as conservative dink-and-dunkers, threw 1.2 and 1.1 yards short of the sticks this season—but when combined with the air yards, time to throw and aggressiveness data, Brady's low yards-to-sticks figure paints a pretty clear portrait of a quarterback quickly flinging lots of short, easy passes to open receivers.

Aha! Patriots fans shout, looking to poke holes in any "Brady is fading" hypotheses. Brady has always thrown short, easy passes to open receivers. You aren't describing a limitation in his game. You are describing the strength of his game: the ability to quickly read defenses, identify open targets and deliver the ball to them in space!

This is true, to a point. Perhaps we should take a look at the three-year trend in Brady's Next Gen Stats. While his time to throw hasn't changed much since 2016:

Brady's intended air yards figure was 9.0 per attempt in 2017, 1.4 yards per attempt higher than this year's. His 2016 figure was 8.1.

Brady's completed air yards figure was 6.6 in 2017 and 6.3 in 2016. The differences seem small until you multiply 0.7 or 1.0 yard per completion by a few hundred completions.

Brady's aggressiveness percentages were 17.0 in 2017 and 17.6 in 2016, far higher than his 2018 rate of throwing into traffic.

So Brady isn't dinking and dunking compared to his Randy Moss days. He's dinking and dunking compared to what he did in his last two seasons.

In fact, a deep dive into the three-year data at Next Gen Stats shows it's rare for a successful quarterback to average in the ranges of 5.6 air yards per completion and 14 percent aggressiveness, as Brady did this season. There are lots of names like Keenum, Cousins, Joe Flacco, Eli Manning, Tyrod Taylor and Blake Bortles in that range, many of them quarterbacks who get criticized (often rightfully) for playing it far too safe and limiting their offenses.

Brady's numbers suggest not an All-Pro but a...(bracing for impact)...veteran game manager.

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Third-Down Decline

By now, Patriots fans are hulking out of their old Wes Welker jerseys and composing none-too-polite tweets for me to savor at my leisure, so let's clear this up right away: No one is comparing Brady to Bortles, Taylor or the recent versions of Eli or Flacco. And "game manager" is only an insult if you want it to be: Avoiding sacks and playing smart situational football are skills, and Brady excels in those areas.

But even the raw data point to obvious weaknesses in his game.

Let's give the Next Gen Stats a break and focus on a straightforward stat split: third-down passing, a fairly reliable indicator of a quarterback's contribution to the offense.

Here are Brady's three-year splits, as well as his career averages and the 2018 NFL rates, on 3rd-and-4 or more yards to go. I avoided short-yardage passes because no one would seriously suggest Brady has forgotten how to find Julian Edelman on 3rd-and-2. We're looking for longer, trickier throws:

Brady in 2018: 50.5% completion rate on 3rd-and-4-plus; 34.3% conversion rate for 1st downs

50.5% completion rate on 3rd-and-4-plus; 34.3% conversion rate for 1st downs Brady in 2017: 55.9% on 3rd-and-4-plus; 41.4% for 1st downs

55.9% on 3rd-and-4-plus; 41.4% for 1st downs Brady in 2016: 65.3% on 3rd-and-4-plus; 43.2% for 1st downs

65.3% on 3rd-and-4-plus; 43.2% for 1st downs Brady in career: 57.6% on 3rd-and-4-plus; 39.8% for 1st downs

57.6% on 3rd-and-4-plus; 39.8% for 1st downs NFL average in 2018: 58.9% on 3rd-and-4-plus; 36.2% for 1st downs

So Brady's completion rates and first-down rates on 3rd-and-4-plus are down from his 2017 and 2016 numbers. They are also down from his career rates, which were largely compiled in a less pass-happy era.

Brady's third-down numbers are also below league average in 2018. It's just one more indicator he's slipped, rather significantly, not just from his career peak but also from his 2016-17 performance level and the standards we would normally apply to a top-tier quarterback.

The Goat in Winter

None of the data presented in this column come as a surprise to anyone who has been carefully, objectively watching the Patriots all year.

The Patriots have been compensating for Brady's limitations with run-heavy game plans (see Week 16 against the Bills) and lots of screens and swing passes (James White led the team in both targets and receptions).

Brady still has the touch, accuracy and decisiveness to deliver some big throws, and familiar targets like White, Edelman and Rob Gronkowski can still beat coverage and help him turn short passes into big gains. But opponents like the Titans, Dolphins and Steelers have successfully choked off Brady's short-passing options, challenged him to throw downfield and come away with victories.

The Chargers, with a withering pass rush and an innovative seven-defensive back personnel tactic, surely have a clear handle on what Brady can and cannot do and what they will be able to take away. But Bill Belichick and Josh McDaniels know Brady's weaknesses too, having helped conceal them for a while.

Brady is old, and his skills are slipping. The numbers don't lie. It's only controversial among those who don't want it to be true.

There is still no quarterback in the NFL—no, not even Foles—more dangerous with the ball in his hands in the fourth quarter of a Super Bowl than Brady.

But this year, Brady is going to need more help than ever to get into that situation.