Decades before Rocky Balboa fought a fictitious bout at the Philadelphia Spectrum, the authentic, original Rocky endured one of the all-time great battles en route to the world heavyweight title at Philadelphia Municipal Stadium.
The date was Sept. 23, 1952. Heading into the late rounds, 29-year-old contender Rocky Marciano already had been knocked down for the first time in his career. His quest for a 43rd career victory without a loss appeared in jeopardy. But when Marciano dropped champion Jersey Joe Walcott "like flour out of a chute" in the 13th round, the new heavyweight king forever cemented his legend in the annals of boxing lore.
Even today, graying boxing fans speak of Marciano with an almost religious reverence, always noting first and foremost the "equalizer" that was the heavyweight's right hand.
Marciano was small for a "big fellow," standing a mere 5-foot-10 and weighing 185 pounds. He moved with the grace of a man trudging through a bog. But the Brockton, Mass., native's right could, by all accounts, take down a Loxodonta Africana. Well, perhaps not an elephant, but certainly an opposing pugilist.
"He was brutally strong," says sportswriter John Schulian, who grew up following Marciano. "When you got hit you stayed hit."
Yet it is the talk of "The Streak" that Marciano's devotees savor, his unbeaten run that began in March of 1947 with a third-round knockout of Lee Epperson.
That KO became Marciano's calling card, which he delivered personally to 43 victims. That swath of destruction included Walcott (twice), Ezzard Charles, Joe Louis and finally, on Sept. 21, 1955, in the ninth round of the seventh defense of Marciano's world title, Archie Moore.
Then, with an unblemished 49-0 record, Rocky Marciano hung up his leathers for good -- retiring as the only undefeated heavyweight champion in history. This year marks the 50th anniversary of that achievement.
It is one of sport's most hallowed accomplishments. Yet some historians have opted to resist the Marciano bandwagon.
As one famed trainer reportedly said, "Show me a fighter who's undefeated and I'll show you a fighter who hasn't fought anybody."
The critics' primary grievance has always been the age of Marciano's aforementioned marquee opponents (all of them were easily old enough to run for president).
Yet age does not always bespeak talent.
"Sure Charles wasn't the fighter he once was and Louis was shot," said boxing historian and former ESPN analyst Max Kellerman. "But for their first fight, Walcott was in his prime and Moore was a legitimate contender into his 40s."
Some detractors claim Marciano benefited from favoritism. Some allege that slick, undefeated heavyweight Roland LaStarza was robbed in his first bout with Marciano.
There is some validity to the accusation that Marciano might have found himself the beneficiary of a bit of luck, but luck is an inherent part of any monumental streak.
Even Joe DiMaggio benefited from luck during his 56-game hitting streak when -- on two occasions -- borderline errors were ruled hits.
Others, such as Don King matchmaker Eric Bottjer, question the validity of Marciano's unbeaten record.
"The streak is bogus," he said. "It's not unique. Gene Tunney had a longer unbeaten streak [52 fights], and Marciano wasn't the only champion to retire undefeated; just look at flyweight Ricardo Lopez [ret. 2001]."
Although both claims are true, both Tunney and Lopez incurred a "blemish" -- a draw -- during their respective streaks.
But even Marciano's most stringent naysayers acknowledge the streak is significant on many fronts.
The first, and perhaps most obvious, is the mode in which he disposed of his foes, as if he took it personally that they were trying to blemish his record.
His 88 percent career knockout rate surpasses that of Mike Tyson (78 percent), Sonny Liston (78 percent) and far exceeds that of Muhammad Ali (66 percent).
Secondly, even critics acknowledge that 49 consecutive victories speaks of Marciano's indefatigable work ethic. Marciano's monastic training regimen was no secret; the man so easy with a smile out of the ring conditioned himself with a seriousness like no other heavyweight in history.
Long runs and healthy living were a part of daily life. Marciano ignored the distractions of money and fame.
But the single-most impressive aspect of the streak was not a result of Marciano's action, but his restraint. Unlike so many other fighters in history, he resisted temptation to step back in the ring.
Considering the toll fighting takes on the body, retirement would seem like the most appealing option. It is not.
For one, there are obvious fiscal considerations. Few fighters have ever donned gloves to climb out of the suburbs, including Marciano, whose devotion to the dollar bespoke of his impoverished childhood in the shadow of the Brockton shoe factories.
"It's so hard to retire undefeated," says HBO analyst Larry Merchant. "You used to work so hard for peanuts and now you're getting your due. When you're at the top, a marquee name, you think one or two more fights couldn't hurt."
It often does, however. Merely look at Tyson, Larry Holmes and particularly Ali.
But there is more to it than a bottom line. Fighting is, simply, what fighters do best. For some, it's all they know. It's who they are.
Champions are master craftsmen, using their hands in lieu of a brush or a pen. Imagine if Picasso put away his oils at the height of his fame? Or that Hemmingway never wrote another book after "The Sun Also Rises"?
Stepping out of the ring undefeated might just be the hardest decision a fighter makes in his life.
"There's the old saying that every athlete dies twice," said Schulian. "Once, when he takes his last breath and the other when he hangs it up."
Why then, did Marciano retire when he did?
Experts have cited a number of reasons.
His lumbering style -- preventing longevity -- might have been a factor. There was also a dearth of quality opposition.
And there was Marciano's bitterness after discovering manager Al Weill had his hands in the proverbial cookie jar.
Yet the reasons might run deeper.
Though far from a man of letters -- as a teenager, Marciano opted to spend his days at James Edgar Playground rather than his high school -- a lack of education never squelched his powerful sense of pride.
"He wasn't aware of the importance of the legacy," says biographer Everett Skehan, whose book on Marciano, "Undefeated: Rocky Marciano -- The Fighter Who Refused To Lose" is being released this fall.
"But he knew he wouldn't end his career with a loss."
Marciano's career perfection remains one of the monumental individual streaks in sports history.
But on this, the 50th anniversary of his retirement, where does this streak stand in comparison to others?
The answer is not easy, as there's no computer program or mathematical formula for such a question. Polling sports fans on the significance of streaks is similar to polling a roomful of economists about the country's current standing. It's a safe bet they'll all somehow provide different, yet equally persuasive answers.
Record books hold notable individual sports streaks as varied as a Ben and Jerry's sampler.
Were Marciano's fights more exhausting than Lance Armstrong's seven Tour de France victories?
Did winning 49 bouts without a loss require more concentration than Tiger Woods' 142 straight tournaments without missing the cut?
Did Marciano exercise as much patience as Orel Hershiser did in recording 59 consecutive scoreless innings? Was it a greater show of endurance than Brett Favre's 227 consecutive starts (regular and postseason as of Sept. 21) at quarterback? Did Marciano exhibit any more talent than DiMaggio did during his 56-game hitting streak?
The answer to all of the questions is yes, no and maybe.
Streaks are subjective in nature, valued in varying degrees by those who hold them in esteem. One man's miracle is another man's matter-of-fact accomplishment.
Until sports fans no longer look upon Marciano's streak as one of the all-time greatest, it will remain one of the all-time greatest. When the Brockton native died in a 1969 plane crash, he wasn't considered the best heavyweight in history. That has not changed.
Boxing cognoscenti have never held Marciano in the iconic class of Johnson, Dempsey and Ali.
But retiring undefeated, as no other heavyweight fighter had before or has since, has elevated a simple man from Brockton to a status all his own.
"His streak doesn't make him a greater fighter," said Merchant, "but a larger figure."
And as the modern fight game changes, with boxers finding themselves with fewer and fewer opportunities to prove themselves in the ring, Marciano's 49-0 streak might remain in the record books as long as it will in the memories of the fans who adore him.
Tim Struby covers boxing for ESPN The Magazine.