Fifty years ago, the kind of play that logically should have happened only once began to occur with regularity.

It happened on ABC’s “Monday Night Football,” Steelers at Chiefs on Oct. 18, 1971, thus a national prime-time audience helped create a national sensation. Steelers receiver Dave Smith caught a pass from Terry Bradshaw and was on his way, alone, to the end zone when he needlessly, carelessly, mindlessly raised the ball in his left hand.

The ball fell from his hand and rolled through the end zone for a touchback. Pittsburgh lost, 38-16. Career infamy for Smith, who passed this past May.

Smith’s foolishness stood — and stood out — alone for a while, but has since been joined by scores of similar episodes on every level — Pop Warner, high school, college and professional. What existed as an anomaly is now a persistent occurrence.

In fact, again on “Monday Night Football,” Eagles WR DeSean Jackson, against Dallas in 2008, sacrificed his first NFL TD to a cool and casual, check-me-out ball flip — only he had not yet crossed the goal line.

Two weeks ago, Seattle WR DK Metcalf caught a long pass then slowed to hold the ball with one hand in preparation of a self-celebration as he scored. However, from his blindside, surprise! The ball was swatted away for a touchback.

Why? Why would players risk such infamy and team destruction? Where are the coaches to insist, from Day 1, that their players protect themselves and their teams at all times by securing the ball and not committing acts of worthless, self-indulgent stupidity?

Why have episodes of the senselessly self-destructive grown thick in 50 years, rather than withered and blown to dust?

This past Sunday, Chargers defensive back Michael Davis intercepted a pass and was running for a TD. When he reached the 10, he slowed to raise the ball over his head with one hand. He got away with it.

On CBS, Ian Eagle and Charles Davis were unmoved by Davis’ ignorance of recent and older history or his temptation to turn a guaranteed TD into something needlessly riskier. They said nothing.

DK Metcalf
DK MetcalfAP

But had Davis dropped that ball or in any other way lost his grip on it, he’d have been accused of stupidity in the first degree.

Great catch so close to being three-run blunder

There are always alternative ways to look at things. Thursday, top of the second, bases loaded with Braves, no score, one out. Nick Markakis hits low liner to Marlins left fielder Corey Dickerson — who makes a great, full-out diving catch. FS1’s Adam Amin explodes, “To save a run!”

Perhaps, but it seemed that Dickerson’s decision came closer to costing the Marlins at least three runs.

But Amin brings to Fox what he likely mastered at ESPN: hype.

Thursday, he suggested that we be blown away by Braves pitchers’ .096 ERA during this postseason. But these are the playoffs following the lowest regular-season team batting averages in history, so …

He also delivered an upbeat lecture on how “the game continues to evolve.” The game has been lost to home runs, strikeouts or walks, the senseless removal of effective pitchers, unintended replay stoppages and games mindlessly stretched to midnight. That meets with his sense of evolution?

Game 1 of Padres-Dodgers was won, 5-1, by Los Angeles. It ran 8 ½ innings, 4 hours, 14 pitchers, 21 strikeouts, 14 walks and just seven hits. Any more evolvement and we’ll have to order our Amazon loincloths on Amazon.

But Amin does have an honest sense of humor. At 7-0 Atlanta, late in Game 3 on Thursday, he led a time-filler chat that he admitted was caused by the score.

What TV folks ignore: It’s hardly a shock that Jalen Ramsey keeps playing down and dirty Family Feud with Giants WR Golden Tate. Ramsey has been a career pain in the carcass — from missing practices, to fistfights with teammates, to demanding trades, to a suspension for misconduct.

One of his last acts before forcing a trade from the Jaguars to the Rams was to show up at practice in an armored truck, insisting the Jags fill it with money.

Yet all you hear from TV’s game commentators is how Ramsey is such a great player. He’d better be, given his conduct.

Of course, pandering Roger Goodell and the NFL’s partner TV networks would never offend the most offensive. They’d offend us, first.

Vulgar ‘classic’ in NLDS

For those who missed the Padres’ Manny Machado three times screaming “F–k you!” at the Dodgers during Game 2 of their NLDS, Fox and ESPN made sure to replay it.

Machado was furious at Dodgers pitcher Brusdar Graterol for his excessive celebration — he threw his hat and glove off the mound, acted like a jerk — in response to teammate Cody Bellinger’s robbery of a Fernando Tatis blast.

Apparently, Machado forgot that earlier in the game he had performed an excessive bat-flip on a home run.

But ugly sideshows have become the main attractions at Rob Manfred’s House of Cheap Thrills — now often explained, excused, rationalized or confused as “good, clean fun.” MLB’s website classified the game “a classic.” It might’ve been — had it not been stuffed with unfiltered garbage.

There was only one number for me growing up: No. 16. Whitey Ford from March through early October, Frank Gifford from fall into winter. In pretending to be Ford, I’d “pitch” into a full-length mirror in our hallway in order to be a lefty, like Whitey. I got to know him, swapped some letters, too. I’ll continue to cherish them, only more than ever.

At $17.5 million per, it remains difficult to fully hear what Tony Romo is saying. His raspy voice often fades at the close of his spoken thoughts. CBS can’t fix that?

Sports gambling talk and advertising have become so prevalent on WFAN that according to fabricated sources, management is considering teaming Craig Carton and JJ Jastremski on a gambling show titled “Null & Void” or “Insufficient Funds.”

Given this is the time of year when baseball’s postseason stats are conflated to create bogus history, we recall the time ESPN reported that Bobby Thomson’s home run “won the 1951 NLCS.”

If someone whispered to Matt Vasgersian that doubles in the gaps are now called “squibble gappers,” he’d call the next one he sees on the air a “squibble gapper.”

Unless it’s designed only for us to marvel at the latest advanced technology to advance the science of useless gizmos, that T-Mobile “Base-Cam” is a waste. Worse, the base dirt it kicks up on indiscernible plays makes me hanker for chocolate milk.