When Tom Dempsey walloped a 63-yard field goal for the New Orleans Saints in 1970, it might have ushered in a new era of long kicks. Instead, it was an anomaly, so much so that it took decades for another kicker to match it.

It has taken 51 years to nudge the N.F.L. record 3 yards longer, as Justin Tucker of the Baltimore Ravens did on Sunday with a 66-yard field goal. It’s worth asking: Why have field-goal records generally stood for so long, and why are they broken by such small margins?

Dempsey’s kick, with two seconds left, won the game for the Saints over the Detroit Lions at Tulane Stadium. It shattered the previous record of 56 yards set in 1953 by Bert Rechichar of the Colts — a defensive back attempting the first field goal of his career.

“The snap was perfect, the ball was placed perfectly — and I had the strength,” Dempsey said a day later. “I’m still stunned today thinking about it.”

Besides that kick, Dempsey, who died last year at 73 of complications from the coronavirus, is remembered for his footwear. He was born without toes on his right foot, and when kicking, he wore a custom shoe with a flattened toe surface.

The 63-yarder passed into N.F.L. lore and was unsurpassed for 43 years — 20 years longer than Bob Beamon’s epic long jump at the 1968 Olympics, which has become synonymous with paradigm-shattering records.

There was just one kick of 60 or more yards in the 1980s and two more in the 1990s: In 1998, Jason Elam of the Broncos tied Dempsey’s record.

But the new century brought bigger, stronger, more skilled kickers and an explosion of successful 60-plus-yard kicks, 21 of them so far. In 2013, the Broncos’ Matt Prater finally broke Dempsey’s record with a 64-yarder.

On Sunday, Tucker went 2 yards better, booting a 66-yard field goal as time expired. The ball hit the cross bar, popped in the air and fell through the uprights to win the game for the Ravens.

In a small coincidence, both Dempsey and Tucker’s game winners came against the Lions. In a huge coincidence, both games ended with a 19-17 score.

“I don’t really have the words to do justice to the moment,” Tucker said after the game.

The comparative onslaught of successful long kicks in recent decades can be attributed to kickers getting bigger and fitter, and improvements in technique, beginning with the switch to soccer-style kicking. Many stadiums are also domed now, cutting down on wind and weather impediments.

Still, the record has increased only 3 yards — nine feet — since 1970. Why is that?

Teams don’t try them.

It’s not that field goals have fallen out of favor: The number of attempts per team is flat over the last six decades. Field-goal kickers have become a lot more accurate since 1970, making 85 percent of their kicks last season to just 59 percent then. In theory, they should have the ability to make a lot more long kicks than they do.

But to kick a really long field goal, teams have to attempt a really long field goal, and such tries are not routine. In the 2020 season, 168 field goals of 50 yards or more were attempted. Only 10 of those were 60 yards or more, and just three were 65 yards or more.

One reason is field position. If an attempt from midfield fails, the opponent gets the ball at the place the ball was spotted. Even a poor punt that resulted in a touchback would give the other team the ball at its own 20.

It’s no coincidence that Tucker’s kick came with time running out and the game on the line. Field position considerations mean you probably only want to try a very long kick as time is expiring in the half or in the game. And if it’s the fourth quarter, there’s no point trying a long field goal unless you are within 3 points of your opponent. That combination of circumstances doesn’t come up too many times a season.

Hail Marys are a better bet.

Quarterbacks’ arms are improving as fast or faster than kicker’s legs. A Hail Mary try may be just as appealing as a long kick to many coaches. Teams have also started treating long passes more scientifically, setting up special blocking schemes and analyzing opponents’ tendencies, rather than simply chucking up the ball and praying.

Besides, Tucker’s 66-yarder just barely made it over the bar. The Canadian Football League record is 62 yards, and the major college record, without a kicking tee, is 65. Kickers have sometimes belted 70-plus-yard field goals in practice, but in a game, how much longer can a kicker truly go?

Falling short can have ugly consequences.

There’s one more rude downside to trying a really long field goal. Also on Sunday, Prater of the Cardinals took a shot at a 68-yarder against the Jaguars as the first half ended. Had he made it, Tucker’s kick would have been an afterthought.

But Prater came up short on the prodigious kick. And the thing is, you can return a field goal that comes up short. Jamal Agnew caught Prater’s short kick and ran it back 109 yards for a touchdown. A play that had a small chance of getting the Cardinals 3 points gave the Jags 6 instead.