Steve Buscemi in “Boardwalk Empire.” (Macall B. Polay/HBO)

In the talk about how television has improved over the last two decades, viewers often forget to credit a slight shift in industry etiquette that made cancellation a kinder, more creative process — at least in some cases. Good manners can make good TV series, and it’s hard to think of anything more respectful than giving a showrunner one last season, even after the buzz has faded to a distant hum, to wrap his or her story up definitively and artistically. It’s a kindness that rarely involves the word “canceled.”

Nothing’s canceled anymore, even when it is. Though the practice is increasingly common on broadcast networks (“Parenthood,” “Parks and Recreation” and “The Mentalist” are all being gently concluded rather than taken out back and shot), premium cable networks have become the real experts at these end-of-life “final season” rituals because they can afford to extend the favor.

The noble death thing is not always successful. It depends on the attitude of the show’s producers, writers and cast: Will “the end” become a forced march of contractual obligation or will the show take this opportunity to outdo its best work? A couple of recent examples of squandered epilogues would include the final seasons of HBO’s “True Blood,” which took the chicken-without-a-head approach, and the network’s New Orleans drama, “Treme,” which acquiesced to its more sentimental impulses instead of departing on a surprising or even memorable note.

“Boardwalk Empire,” Terence Winter’s consistently downbeat yet exquisite attempt to fictionalize the rise of organized crime during Prohibition, will conclude its fifth and final season Sunday night on HBO.

(Here’s the usual spoiler alert: If you’re not caught up through the Oct. 19 episode, be warned that I’ll be making some specific references to what’s happened.)

The network gave Winter and his colleagues — a long list of top-tier writers/producers that includes Howard Korder and directors such as Martin Scorsese, Tim Van Patten and Allen Coulter — just eight episodes to braid the loose ends together and wrap up a story that has slowly grown to epic proportions, all of it in grand orbit around Steve Buscemi’s unforgettable performance as Enoch “Nucky” Thompson.

Rather than blow off excess steam and merely deliver a body count, the writing and acting in season 5’s episodes have surpassed “Boardwalk Empire’s” usual high standards, offering a pitch-perfect conclusion to a story that is surprisingly human in a world that’s been intentionally strewn with subhuman behavior. After using the context of actual crime history (Al Capone, Lucky Luciano, Meyer Lansky, et al.) to expand its tale from Atlantic City to Chicago, New York, Florida and even Cuba, “Boardwalk Empire” has now retracted to what it perhaps always meant to be: a rumination on the state of Nucky’s soul.

That’s not to say that “Boardwalk Empire” looks as if it intends to end on a sappy note; it’s also had plenty of what both the casual and devoted viewer expect: Lots of people have been shot in the head, the neck, the chest. So long, then, to Nelson Van Alden/George Mueller (Michael Shannon), Chalky White (Michael Kenneth Williams), Mickey Doyle (Paul Sparks) and Sally Wheet (Patricia Arquette). It goes without saying that “Boardwalk Empire” was a relentlessly violent show, befitting its genre.

It was also macho. This didn’t mean that the show was necessarily misogynist (and when it was, it could fall back on historical precedent as an excuse) or without female fans (I happen to know many women who’ve followed each season faithfully), but it does mean that the show asked viewers to care primarily about the men portrayed in it.

The women of “Boardwalk Empire” (most notably Gretchen Mol as Gillian Darmody and Kelly Macdonald as Margaret Schroeder Thompson) gave superb performances when called upon to do so and yet were never given the prominence they should have had.

And, while we’re on the subject of manliness, there was Winters’s resolute choice for “Boardwalk Empire’s” theme song, a bluesy 1990s instrumental riff from a band called the Brian Jonestown Massacre, which struck many as a strangely anachronistic way to open a show that lavished attention on its 1920s-’30s period details. I found the theme to “Boardwalk Empire” to be sonically and almost unbearably masculine, like the music from ads for erectile-dysfunction pills. It’s a sound I will forever equate with the concentration “Boardwalk Empire” demanded of its viewers, asking them to follow along as a parade of nearly indistinguishable thugs and crime bosses in suits rushed past.

“Boardwalk Empire” was a hard sell. There was seldom anyone to root for, fully — especially after the death of its best and most compelling character, Richard Harrow (Jack Huston), a facially disfigured World War I veteran who took up, and then tried to turn away from, the coldness of criminal life.

I half expect to be hearing from readers years from now who will discover “Boardwalk Empire” in hindsight and set out to “inform” the rest of us of about it, long after we begged them to watch. Politely we’ll have to tell them: Just wait until you get to the last season. In some ways, it’s the best.

Here are three reasons why:

1 Jumping ahead can put flourish on a finish. To get where they needed to go, Winter and his co-writers boldly pressed the fast-forward button, shifting the story ahead seven years to 1931. This meant they skipped over stuff that might have been included in more seasons of the show, had it ever become the surefire, post-“Sopranos” hit that HBO hoped for. Because the show is a work of historical fiction (loosely so), this deprived viewers of some events between 1924-ish and 1931-ish that we might have liked to have seen, such as the 1928 assassination of New York gangster Arnold Rothstein (Michael Stuhlbarg).

No matter. Moving ahead gave “Boardwalk Empire” renewed momentum. Characters had aged in the intervening years: Nucky began to see the futility of sustaining a criminal enterprise beyond Prohibition. Gillian sat in an insane asylum for those years; Margaret started her life over in New York; Chalky White endured prison and hard labor. This should be Step 1 for writers faced with the certainty of a final season: Consider moving the story ahead five or 10 years. It’s almost like imagining what the reunion show or series reboot would have been like. (Hey, it sort of worked for “How I Met Your Mother.”)

2 Flashbacks can still be a powerful storytelling tool. When this season began, some fans grumbled that, in addition to flashing forward, “Boardwalk Empire” had taken the flashback route, putting us in the late 19th century for the somewhat depressing misadventures of the young, neglected Enoch Thompson (Nolan Lyons), whose honesty slowly erodes as he begins to work for Atlantic City’s sheriff and first encounters the nefarious (and pedophilic, it turns out) Commodore.

Flashbacks get old, and too many shows use them too much. But within a few episodes, it became clear that “Boardwalk Empire’s” flashbacks were being offered almost as a gift to its most ardent fans, particularly as Marc Pickering (a dead-ringer for a younger Steve Buscemi) took over the role as Nucky as young sheriff’s deputy married to his first love, Mabel (Maya Kazan), and falling inexorably into the darkness that will define him.

3 The art of keeping one last secret. Will Nucky die in the final episode? Will he be somehow redeemed? Does he need to be, really? (Would “rescuing” Gillian from the asylum suffice?) Is “Joe Harper,” the strangely well-mannered kid who has been hanging around Nucky’s operation, merely there to act as an analog to young Nucky, reminding the older Nucky (and viewers) of the meaning of innocence? Or is the kid in fact Tommy Darmody (as so many fans have hoped), the orphaned son of Jimmy (Michael Pitt)? If so, is he back for closure or revenge or neither?

Every great story keeps a few secrets to itself. In a season of spilling truth along with the blood, “Boardwalk Empire” has filled in many of its blanks, but not all of them. It would be fitting, somehow, if this show that deserved many more viewers and much more attention would creep away quietly — even ambiguously — leaving us wanting that little bit more that we’ll never get.

Boardwalk Empire (one hour) series finale airs Sunday at 9 p.m. on HBO.