Inside the NFL's 4th-down numbers and this season's interesting trend

How aggressive are NFL coaches on fourth down? There are a few ways to answer the question.

• They're more aggressive than they were five years ago before an analytics wave convinced teams to kick and punt less. But the trend is easing this season. Football gluttons who watched every game in an average week in 2021 could expect to see 46.6 fourth-down tries, or 1.46 per team. That slipped to 42.3 (1.32 per team) entering Week 9.

• They're more aggressive than in the past on fourth-and-2. Attempts from that distance have risen and represent more than 15% of fourth-down tries. Coaches are confident that offenses can gain the extra yard.

• They're less aggressive than they ought to be. Statistical models exist to recommend what a team should do on fourth down - punt, kick the field goal, or run a play - based on what would maximize its win probability. Ben Baldwin's model shows coaches collectively go for it in the fourth quarter half as often as they should and considerably less so earlier in games.

Fourth-down decisions are always a hot topic. Select coaches tend to drive the conversation.

John Harbaugh trusts the numbers and irks studio panelists by throwing on big snaps when kicking seems safer. Doug Pederson, Brandon Staley, and Kevin Stefanski like to keep the offense on the field. Kliff Kingsbury's Cardinals lead the NFL in fourth-down tries (24) this season. Dan Campbell's Lions roll the dice 40% of the time.

Bill Belichick, Pete Carroll, and Mike Tomlin prefer to kick or punt. Several clubs with first-year head coaches (Bears, Broncos, Giants, Saints, and Vikings) have gone for it far less this season. Five of the league's most cautious teams are division leaders (Chiefs, Titans, Falcons, Seahawks, and Vikings). However, the unbeaten Eagles take their fair share of chances.

Teams especially aggressive or passive on fourth down can be split into quadrants. Each quadrant has a representative squad whose fourth-down calls have shaped their fortunes this season.

Aggressive and unsuccessful: The 1-6 Lions started to give'er on fourth down when Campbell took over as coach in 2021. They've converted nine of 20 tries this season to click at 45% but set a sorry record in Week 5 against the Patriots by failing to convert any of their six attempts.

Detroit could justify its first attempt. Jamaal Williams tried to run for a yard but got stuffed. The math supported kicking a field goal on the next try. Instead, New England stripped Jared Goff on a dropback and scored on the fumble recovery. The Lions' offensive line, usually one of the team's strengths, failed on both attempts, creating no traction on the first snap and failing to block the Pats' five-man rush on the second.

Poor execution limits plenty of teams. The Packers were right to throw on fourth-and-short in the fourth quarter of recent losses. Still, Giants blitzers read and batted one Aaron Rodgers pass, and wideout Romeo Doubs bobbled another against the Commanders. Green Bay is an NFL-worst 2-for-11 on fourth down with seven incompletions.

Baltimore made a defensible decision in Week 4 against the Bills but had a bad outcome. Two yards from the end zone in a tie game, Lamar Jackson backpedaled within the pocket - meaning he couldn't throw the ball away - and heaved an interception that produced a touchback. The Ravens weren't wrong to go for it, but Buffalo drove for the win, and Harbaugh took flak because the gambit bombed.

The lesson: Play selection and execution matter.

Aggressive and successful: Fourth-down prowess is one reason the 8-0 Eagles remain perfect. Assertive in his second season as coach, Nick Sirianni has ordered 16 fourth-down tries, or two per game. Philadelphia has converted 12 - seven via Jalen Hurts keepers and four when he's passed.

Sirianni counts on his ascendant QB to make plays. Ranked fifth in expected points added per play, the mobile Hurts has run for multiple fourth-down touchdowns (in close wins over the Lions and Jaguars) and threw to DeVonta Smith for such a score when Philadelphia topped Washington.

Unfazed by an early fourth-down incompletion against Detroit, Sirianni set up Hurts to gain one yard at the goal line on the next drive. Faking a handoff out of the shotgun, Hurts waltzed in for the TD when his wideout and tight end crossed paths to occupy the strong-side defenders. When the Eagles faced fourth-and-1 from Detroit's 40-yard-line late in regulation, Hurts kept it simple, sneaking up the middle to seal a three-point victory.

The lesson: Position your stars to succeed.

Conservative and unsuccessful: Kyle Shanahan's passivity hurt the 49ers in last season's NFC title game. Up three points early in the fourth quarter and facing fourth-and-2 at the Rams' 45, San Francisco failed to draw the defense offside and punted. Shanahan said he never considered calling a play, unbothered by his decision even after L.A. kicked back-to-back field goals to advance.

The Niners are 4-4 this season, and their 2-for-7 fourth-down conversion rate stinks. But bypassing worthwhile opportunities to go for it is bad, too.

On fourth-and-2 in Denver's end in the fourth quarter of Week 3, Robbie Gould kicked a field goal to build a five-point lead that the Broncos erased in one drive. On fourth-and-3 from Kansas City's 12 on the opening series of Week 7, Shanahan declined to take a big swing, settling for a field goal that didn't move the dial in a blowout loss.

Indianapolis, another middling team, has an identical fourth-down profile (2-for-7 success rate). No team goes for it when the math says they should less frequently than Indy, per Baldwin's model. The Colts kicked a field goal on fourth-and-3 from Washington's 21 last week and wound up losing by one.

The lesson: Sometimes, safe is death.

Conservative and successful: Mike Vrabel's 5-2 Titans don't take unwarranted risks. They're 3-for-4 on fourth down on the second-fewest tries in the league. Baldwin's calculations maintain they've gone for it exactly as often as they should.

Every Tennessee conversion has come on a Derrick Henry carry. He stepped untouched into the end zone from a yard out at Houston last week to boost the Titans' third-quarter lead to 11 points; they won by seven. In Week 5, three receivers spread wide on fourth-and-2 in Commanders territory so Henry could rumble up the gut.

Conversely, Vrabel ordered a season-high eight punts from Ryan Stonehouse against Washington when going for it didn't make sense. Four of those punts pushed the Commanders inside their own 20 and led to Washington punts or turnovers. Tennessee prevailed by four.

Vrabel knows Henry is a battering ram and Stonehouse's right leg is powerful. His selectiveness benefited the Titans in close wins that pushed them to the top of the NFC South.

The lesson: Trust the math and your personnel.

A note about punting

Teams have punted less frequently than ever for the last few years, but Stonehouse, the undrafted rookie out of Colorado State, is powering a literal boom in punt distance. League-wide, the average punt is sailing 47.3 yards this season. That's up substantially from the high of 45.6 yards established in 2020 and equaled in 2021.

Shane Lechler set the average punt yardage record at 51.1 in 2009; Stonehouse (54.0 yards) and the Chiefs' Tommy Townsend (52.9) could shatter the mark. If the Raiders' AJ Cole III stays above 50 yards for the second straight season, he'll join Lechler as the only punters who've eclipsed the threshold twice, per Stathead.

Dallas veteran Bryan Anger aired the season's biggest punt last week, an 83-yard rocket in the fourth quarter against the Bears. It was the fourth-longest punt booted in the NFL this century, and it bounced into the far end zone for a touchback.

The Cowboys led by 20 at the time, and their win probability stood at 100%. On that snap, there was no wrong call to make.

Nick Faris is a features writer at theScore.