Ivan Calderon is accustomed to being overlooked. It's easy, after all, when you stand just 5 feet tall. But the little Puerto Rican package of dynamite just might be the best pure boxer in the world.

He moves effortlessly between Spanish and English, dresses in dapper dark gray suits, and is so engaging that he commands attention like a circus ringmaster. And between the ropes he's virtually impossible to hit, winning all 32 of his fights and putting on such a tactical display that he's stopped an opponent only six times.

About the only fight Calderon hasn't won is acceptance for the little guys.

He'll fight on the undercard Saturday night when Miguel Cotto defends his welterweight title against Joshua Clottey at Madison Square Garden. But unless you're inside the sold-out arena, you won't see the 108-pound champ take on top contender Rodel Mayol.

The premium cable network is showing "The Dark Knight" before the main event.

"I want to show HBO that small people need an opportunity," said Calderon, who'll make his 17th title defense. "At least the HBO people will be there to show them what I have, and keep on putting me in their eyes."

That'd be a good start, because his last two fights have been in Puerto Rico, and before that New Mexico _ not exactly a boxing hotbed. He's fought everywhere from Oklahoma to Arizona to Las Vegas, taking whatever he can get, which usually isn't much.

Smaller fighters seem to get a proportional amount of respect, and a proportional payday, compared to their larger counterparts. Most top fighters in Calderon's weight class get less than $40,000 a fight, and although he'll clear closer to $100,000 on Saturday night, that's a far cry from the $1 million that middleweight champ Kelly Pavlik often commands.

"I know what's happening," Calderon said. "They don't pay us the same way they pay the big guys, and I always do better fights. I always get more action."

For years, fans didn't believe that was the case.

Heavyweight icons like Muhammad Ali, Joe Frazier and George Foreman _ all the way back to Joe Louis and Rocky Marciano _ were big fighters who threw big punches, making for dramatic fights and bone-rattling knockouts.

But the current heavyweight division is a mess, with champions in recess and a slew of other ridiculous titles. The Klitschko brothers, considered the only notable champs, will never fight each other. Other hefty classes offer few worthwhile fights _ 175-pound king Bernard Hopkins might go the entire year without stepping into the ring.

That void is being filled by smaller fighters.

It started years ago with Oscar De La Hoya and Floyd Mayweather, and has morphed into the Pacmania that surrounds pound-for-pound king Manny Pacquiao. But even he, despite starting his career at 106 pounds, didn't become a blockbuster attraction until he moved up in weight.

"It's a little less giving," said HBO sports president Ross Greenburg, noting that Calderon has often appeared on pay-per-view. "It takes a certain kind of mix to get on HBO at that weight."

For one thing, it takes a big-name opponent, and there aren't many available.

Nonito Donaire has some name recognition at 112 pounds, a weight at which Calderon might be able to fight. Vic Darchinyan has broken through at 115 pounds, fighting Joseph Agbeko on Showtime next month, but that would be a stretch for the man nicknamed "Iron Boy."

"He obviously has name recognition and is on most peoples' pound-for-pound list," Greenburg said of Calderon. "He needs the guy across the ring."

Calderon holds up his end of the bargain, though, exuding charm and charisma. He once fought Cotto when he was 17 and the current 147-pound champion was several years younger. They both weighed about 100 pounds and Calderon proudly proclaims he won.

Too bad Calderon had already stopped growing.

"He's probably the best boxer in the world today," said Bob Arum of promoter Top Rank. "He's relentless and he's always in a tremendous fight."