We've all heard it, the ebb and flow of the crowd noise at a boxing match, the volume and intensity rising and falling in harmony with the action. It's the soundtrack of excitement, an audio gauge of the level of enjoyment taking place. If the uproar reaches a crescendo, it means the central nervous system has shifted into overdrive.

Gennady Golovkin-Daniel Jacobs TV lineup for the K2 Promotions card on Saturday night (HBO PPV, 9 ET) from Madison Square Garden in New York: •Middleweights: Gennady Golovkin (36-0, 33 KOs) vs. Daniel Jacobs (32-1, 29 KOs), 12 rounds, for Golovkin's unified world titles

•Junior bantamweights: Roman "Chocolatito" Gonzalez (46-0, 38 KOs) vs. Srisaket Sor Rungvisai (41-4-1, 38 KOs), 12 rounds, for Gonzalez's world title

•Junior bantamweights: Carlos Cuadras (35-1-1, 27 KOs) vs. David Carmona (20-3-5, 8 KOs), 10 rounds

•Lightweights: Ryan Martin (17-0, 10 KOs) vs. Bryant Cruz (17-1, 8 KOs), 10 rounds

Our bodies undergo a change when we are excited, releasing a flood of neurochemicals such as adrenaline and dopamine that gives us a rush of pleasure. There are also cells in the brain called mirror neurons, which cause us to internalize the action we are seeing and feel the accompanying emotions as if we are doing the action ourselves.

More often than not it's the boxers who provide this chemical rush on a consistent basis who become fan favorites.

Unified middleweight world titleholder Gennady Golovkin, the sweet-faced assassin from Kazakhstan's coal country, definitely has what it takes to give the nervous system a jolt. That's why he's headlining Saturday's HBO pay-per-view at Madison Square Garden.

Golovkin will be fighting a familiar face in Brooklyn's Daniel Jacobs, one of Premiere Boxing Champions' TV mainstays. He's been carefully nurtured, but only to a point. His first-round knockout of Peter Quillin in December 2015 was impressive, and Jacobs is probably as ready for GGG as he'll ever be.

Regardless of the outcome, how high the fight registers on the excitement meter is the most important indicator of success.

Keith Thurman's decision over Danny Garcia two weeks ago was OK, but it petered out in the second half, the excitement and neurochemicals diminishing accordingly. There were too many stretches in the middle of the fight when nothing really happened.

Even so, CBS's broadcast was the top-rated show in its time slot -- a clear victory for boxing. The hunger is out there, and hopefully Golovkin-Jacobs can get the juices flowing again.

Unfortunately, there won't be anywhere near as many people watching Golovkin-Jacobs as watched Thurman-Garcia, because it's pay-per-view. It's a pity really because the guess here is that, one way or another, Golovkin and Jacobs will find a way to make it exciting.

Unified middleweight world titlist Gennady Golovkin's power is undeniable. Ed Mulholland/K2 Promotions/Getty Images

Unless he trips over the spit bucket and breaks a leg, GGG is going to give us a dose of thrills. He's one of those fighter you just have to watch, even if you know the other guy doesn't stand a chance. That's how riveting he is.

It has to do with aesthetics, attitude and the way a fighter goes about his job. The must-see fighters are the ones who keep the sport going, even at the worst of times, the memory makers who compensate for all the garbage we would rather forget.

That's not the case with Jacobs, of course. He's good, and we're going to find out exactly how good on Saturday. But win or lose, it's questionable whether he'll ever become a must-see attraction. They are a rare breed.

If there's a common denominator among the fighters who obtain the must-see status, it's that they are usually big punchers. It's a built-in advantage. Everybody loves knockouts, and every generation has its share of beloved knockout artists.

George Foreman's comeback is a testimony to the power of the punch. He was a former heavyweight champion, had a captivating backstory and endeared himself by making fun of his fat belly and a love of cheeseburgers. It all contributed to arguably the most successful rebranding in boxing history. But none of it would have mattered if Big George weren't knocking the stuffing out of the guys in the other corner.

Former heavyweight champion Mike Tyson fought 15 times in 1985, winning all of them by stoppage, including a Round 1 KO of Robert Colay. The Ring Magazine/Getty Images

Mike Tyson was a must-see fighter before he completed his first year as a pro. He had 15 fights that year (1985) and won all of them by knockout. The opponents were mere props, moving targets for Iron Mike to mow down. Even so, people couldn't get enough of him. He was a little scary, but that's OK. A hint of menace goes a long way in boxing.

It was much the same with Roberto Duran during his rampaging years as lightweight champion. His intensity was palatable as he stalked his prey, glaring at them with predatory eyes. Duran was mesmerizing. Even when the opponent was Juan Medina, Wellington Wheatley or even Pepe El Toro, "Manos de Piedra" demanded your attention.

Until Manny Pacquiao came along, the must-see distinction had long been the purview of fighters from the western hemisphere. But for much of the first decade of the new millennium, the Filipino southpaw was a spellbinding fighter. His speed, relentless attack and raw aggression had adrenaline and dopamine spewing far and wide.

It made him an international superstar. If "PacMan" was fighting, virtually the whole world was watching. In his prime, he was arguably the biggest global star the sport has produced since Muhammad Ali.

The must-watch status isn't reserved exclusively for boxing's elite. Certain fighters at every level are capable of getting those neurochemicals pumping. We'd be lost without them.

Think of fighters such as Frank "The Animal" Fletcher and Arturo Gatti. Their frightening capacity to withstand punishment and rally from the brink of disaster is the sort of thing of which people never tire.

Then there's the underdog bracket for scrappy blue-collar fighters who beat the favorite far more often than they're supposed to and become, at least for a while, cult favorites.

Grizzled junior lightweight Orlando "Siri" Salido is one of them.

He's a bit like a guy who builds a racecar in his driveway and races corporate-sponsored monsters on weekends. Despite 13 losses, Salido took part in ESPN's 2016 Fight of the Year, a ferocious draw with Francisco Vargas.

There's no single path to follow. Must-watch fighters come in all kinds and sizes. Everybody's taste isn't the same.

For millions, Roy Jones and Floyd Mayweather were must-see fighters, but their appeal was different. It wasn't chiefly excitement that drew fans to them. It was the mirror neuron effect. Their devotees identified with Jones' and Mayweather's astonishing athletic ability and knack for remaining unbeaten. They were, for all intents and purposes, their admirers' surrogates.

Kell Brook, left, was able to hit Gennady Golovkin but at the end, it was GGG that ended up with the TKO victory in Round 5. Richard Heathcote/Getty Images

Golovkin's appeal is that he's exceptional in every aspect of his craft. His footwork and the way he creates punching angles is as much a part of his success as his wicked power. Just watching him sink a left hook to the body is enough to make you gasp. What is more, he goes for the knockout every time, another appealing trait.

If GGG has a problem, it is his negligible fame outside of boxing circles. Each victory brings him closer to crossing over into the general public's awareness, so an impressive performance against Jacobs is essential. At age 34, Golovkin has to move quickly. Only a precious few stay must-see attractions for very long.

Jacobs' supporters see hope in Golovkin's TKO of welterweight titleholder Kell Brook in September 2016. Brook was even on two scorecards when his corner threw in the towel with more than a minute left in the fifth round. Maybe a natural middleweight like Jacobs could put a hurt on GGG if he landed as often as Brook.

It's a precarious hook on which to hang one's hopes, but as much has been done with less.

The Garden will be a massive cauldron of noise and neurochemicals on Saturday night. They work in conjunction, playing with our emotions as the fight unfolds. According to the educational YouTube channel ASAPScience, we keep watching because "we're looking to recreate the physiological excitement [we] can't seem to forget."

I guess that's why once you're hooked on boxing, it's almost impossible to kick the habit.

You make the call: