LAS VEGAS—Wallowing in his wonderful world of what-ifs, Larry Merchant will either end up a certified boxing genius or nothing more than a slick-talking used-car salesman.

And the line separating both outcomes will be defined by two left hands—one “great,” the other “shocking.”

Merchant, whose public musings became the seed of the “Dream Match” between boxing’s biggest name and its acknowledged pound-for-pound champion, dropped by the Wild Card Gym Monday morning to watch Manny Pacquiao work out in preparation for his Dec. 6 bout at the MGM Grand here.

And as the reigning WBC lightweight champion hammered jabs and body shots at sparring mate Rashad Holloway, Merchant could not help but be held in awe that the duel he dreamed up has now become a reality.

“Looking back, I am surprised that it happened,” Merchant said.

Merchant thought of the bout in November last year after a pair of boxing results. Oscar De La Hoya had just lost to Floyd Mayweather Jr. while Manny Pacquiao was coming off a validation victory over Mexico’s “Baby-faced Assassin,” Marco Antonio Barrera.

Feeling that De La Hoya-Mayweather 2 would end up with the same result and that Pacquiao would merely plow through the super featherweight ranks with devastating ease, Merchant put the two names together until the clamor snowballed.

“I thought that this was the best fight that could be made,” said the 77-year-old Merchant.

“Nobody thought about it. But in the history of boxing, great little men have—from time to time—fought good big men. And with elite fighters, the difference in weight is not as important as it is with ordinary fighters.

“A fighter who is really tough at one weight, if he has to fight above that weight, may not be that tough. But there are some fighters who are so good, they can do that.

“And if anybody could do that, you would think it would be Manny.”

Merchant, the respected television commentator, was besieged by critics who called the bout a dangerous mismatch. But he feels he will be vindicated by the time Dec. 6 rolls around—regardless of who wins.

“Boxing, like other sports, needs big events that transcend boxing itself,” he said.

For that to happen though, Pacquiao has to prove that he can hold his own against De La Hoya, who even Merchant agrees is the money favorite.

“He’s the bigger guy,” said Merchant. “Oscar should (also) be the favorite because the unknowns about him—age, inactivity, fighting a southpaw—are those that cannot be measured on a scale or with a ruler.

“Those intangibles we will only get to know once they get into the ring.”

Merchant, who has covered some of the most memorable fights both boxers have fought, feels that De La Hoya’s edge in height and reach will be the key factors of the match, which he feels will be defined by the first three rounds.

“Manny has to find a way to cope with (Oscar’s height edge),” Merchant said. “Oscar’s got a great left hand. His right hand is not much of a weapon.

“And speaking of left hands, that is exactly the same blow De La Hoya has to avoid walking into. Because if his left hand is great, Pacquiao’s is shocking.

“Manny’s greatest weapon is the surprise and quickness of his left hand and we will see if he can land it cleanly and if it will hurt De La Hoya in some way.”

“It is a shocking weapon,” Merchant added. “There are very few left-handed power punchers in boxing and, with Manny, opponents don’t see it coming and that’s why it has a lot of impact.”