WBA welterweight champion Miguel Cotto is now on the other side of a difficult equation in the concussive mathmatics of boxing.

When he was dominating the junior welterweight division, Cotto was considered a big 140-pounder, a guy who had advantages in strength, reach and punching power because he was facing opponents who may have weighed the same but didn't look the same. Now that he's moved up to the welterweight division after taking the WBA title in impressive fashion from Carlos Quintana in his debut at 147 pounds, Cotto will be, in most cases, the smaller man. How he handles that side of the equation and how well his punching power, especially to the body, translates against naturally bigger men will determine his future both in the division and in the long annals of boxing history. Some in boxing would argue it will also determine the short term future of one of boxing's most glamorous and storied weight classes.

At 5-7 and with a reach of 67 inches, Cotto had clear physical advantages against most of the junior welterweights he faced. He was stronger, longer and a more potent puncher. But when one stacks him up against the top welterweights he comes up short, literally, in nearly every matchup. That doesn't mean he won't beat WBO champion Antonio Margarito, IBF titleholder Kermit Cintron, WBC champion Floyd Mayweather, Jr., former champion Shane Mosley or a rising young top contender like Paul Williams. It just means he must triumph over different circumstances and traverse a different landscape to do it.

If Cotto defeats Oktay Urkal on HBO March 3, he has already agreed to defend his title June 9 in Madison Square Garden against former champion Zab Judah. Judah (34-4, 25 KO) has many flaws, including but not limited to an undeniable tendency to wane as a fight progresses, yet he possesses the kind of speed Cotto has never seen before from so big a man and it will come at Cotto from an opponent who stands as tall as he does and possesses a five inch reach advantage. How he fares that night will be a large statement about his future in the division but an even worse scenario, physically, might be if he someday has to face Williams, who stands a lanky 6-1 and would have an almost unbelieveable 15 inch reach advantage (82 inches).

For Williams to have any likelihood of being an opponent for Cotto he would first have to fair well against Margarito, the WBO champion he will face this spring in a battle of tall welterweights. But if Williams (32-0, 24 KO) unseats Margarito and ends up in a unification fight with Cotto he could stand more than a foot away from the WBA champion and still be able to blister him with a right jab from his southpaw stance. For a body puncher like Cotto, that is a sizeable disadvantage to overcome. The price for getting inside against someone built like Williams might well be a high, and painful, one to pay.

Would Cotto do it? That depends on who you talk to.

"He's facing the exact opposite of the equation he had as a junior welterweight,'' veteran trainer and ESPN fight analyst Teddy Atlas said. "A guy like Williams could fight at 154 or even 160 in a blink of an eye. Cotto has to show he can deal with that. He was a monstrous guy for a junior welterweight. He doesn't have that advantage any more at welterweight so don't go crazy over what he did against Quintana. Quintana was a guy who didn't deal with pressure very well and Cotto is all about pressuring you. That effected Quintana but it won't effect some of the other guys he might have to face. Williams would be a guy like that.''

That list might very likely include Margarito, who stands 5-11 and has a 73-inch reach, or Cintron, who has the same size and reach edge on Cotto as the WBO champion. Mayweather stands only an inch taller at 5-8 but would have both a five-inch advantage in reach and a clear edge in speed. And someone like former world champion Shane Mosley (44-4, 37 KO) would have a solid seven inch advantage in reach and is a guy who has proven he can win world titles at 154 pounds so he would very likely also possess an edge in strength, if not necessarily punching power as well.

Fortunately for Cotto, boxing is not simply about who stands taller, has a broader wingspan or even can punch the hardest. It is a mystical combination of various physical and mental attributes, most of which Cotto seems to have in abundance. In the not unbiased opinion of his uncle and trainer, Evangelista, "He will destroy anyone at 147.'' Evangelista Cotto might be right about that but if he does it will only be after confronting different problems from the ones he was compelled to face as a junior welterweight.

Certainly Cotto's welterweight debut was impressive, taking apart the previously unbeaten Quintana in five rounds. That answered some questions for J. Russell Peltz, the Hall of Fame promoter and matchmaker from Philadelphia who has seen all the great welterweights of the past 40 years come and go. He's not sure yet where Cotto will ultimately fit but he believes he's competitive with any of the top half dozen fighters in the division today, with the exception of Mayweather.

"He's not as bad as his critics think he is and not as good as his advocates think he is,'' Peltz said. "But for this day and time he is a tremendous puncher. The Quintana fight was the most impressed I've been with Cotto. I thought Quintana was a live underdog and he took him apart.

"I don't know too many fighters who would be competitive with Mayweather at 147 but other than that Cotto fits in there with everyone. Even against Mayweather he would have the kind of power and the body attack to give him a difficult night.''

Veteran matchmaker Carl Moretti, who recently became vice president of Lou DiBella's promotional company after spending most of his career making matches for Kathy Duva's Main Events, looks at Cotto and believes moving up in weight will actually help the new champion despite the fact he will have given away the physical advantages he used to hold over opponents like Paulie Malignaggi.

"He was struggling to make that weight,'' Moretti said. "That was probably sapping some of his strength. Now he'll be at full strength. I think he'll be stronger at 147 but the thing that will serve him best is that he never loses his poise in the ring. He keeps his chin tucked and never deviates. Even when he's been rocked a couple of times it was tough to get him out of his game. A lot of people think he's just a guy who walks forward throwing punches but when he's been hurt he knew when to stop and box. Excluding Mayweather, he's one level up from most of the guys in that division.

"Cotto isn't a one-punch knockout guy. He's got thudding power in both hands. (Sonny) Liston power. He doesn't knock you out with one shot but when he lands you feel it...and it hurts. I don't know what young guys coming up would give him a run for his money. If Mayweather is No. 1 in the division, Cotto is 1A.'' That would make him among the best fighters in the world, for Mayweather enters his May 5 showdown with Oscar De La Hoya at 154 pounds considered to be the pound-for-pound best fighter in the world. To be considered 1A to Mayweather's top dog status is nothing to be ignored or underestimated.

Yet part of the fascination surrounding Cotto comes from the air of danger that always seems to circle around him. On the one hand is the power that has stopped 23 opponents on the way to a perfect 28-0 record, especially from the kind of crushing body shots few of his contemporaries even try to throw.

On the other hand, there have been the nights he was dropped by lightly regarded Ricardo Torres, given all he might ever want from Lovemore N'Dou and badly wobbled by DeMarcus Corley. Corley in fact appeared on his way to a possible upset when he stunned Cotto in the third round after having been dropped himself in the first, but Cotto sensed immediately the situation he was in and, as Moretti points out, switched tactics and boxed conservatively adn wisely until his head cleared. When it did, he ended up stopping Corley after driving him to one knee from a body shot two rounds later.

The end was much the same for poor Torres and Cotto forced Quintana to end his quest for the welterweight title after five rounds as well because of the beating he was taking. Hence it is clear that while Cotto's defense may at times be suspect and the firmness of his his chin an issue yet to be settled, his heart is not, as Joe Frazier once put it about a flagging opponent, "pumping Kool-Aid.''

"I do feel his chin is a little suspect,'' Hall of Fame West Coast matchmaker and promoter Don Chargin said. "When he was fighting at 140 he was huge compared to other guys. Now he's in with guys naturally bigger than he is and that may negate some of the power that bailed him out in fights where he got hurt but he's also a guy with a good assortment of punches. A lot of ways to attack you. He throws nice combinations and he has a great left hook to the body.

"To me, the verdict is still out on him against the top 147 pounders but you know one thing about Cotto. He's coming to try and hurt you.'' Although he at times has shown some affinity for boxing, especially in the few times he was in trouble, in the end Cotto accepts the inherent dangers of the warrior's approach and seems willing to pay the price of occasionally bleary eyes for the opportunity to destroy whomever is put in front of him. Thus far, that has been a formula that has made him both a two-time world champion and a hero in his native Pureto Rico like none there since Felix Trinidad was at his height.

"Quintana was a good fighter but my shots were bigger (than his),'' Cotto said after winning the WBA form of the welterweight title. "He didn't stand up to them. When you fight at this level you expect both fighters to have their moments.''

In the end, it may be that stout heart and ferocious approach to a most dangerous business that answers what few questions are left to be asked about Miguel Cotto. Can he cope with larger, more natural 147 pounders? Will his chin hold up against assaults from heavier handed welterweights like Cintron (27-1, 25 KO), quick handed ones with a reach advantage like Mayweather (37-0, 24 KO) or veterans who have won world titles in heavier weight classes like Mosley (44-4, 37 KO)?

Those are questions that remain to be answered, which is why Atlas, for one, was anxious to see Cotto challenge Margarito, a fight that seemed destined to happen in June until the latter opted to fight a mandatory defense against Williams that more than a few boxing experts feel could be disasterous for the WBO titleholder.

"Like anybody he has flaws,'' Atlas said of Cotto. "You can find him. Sometimes he punches from too far out and leaves gaps where he can be countered or beaten to the punch. But I think he has a good chin and more importantly he has a very stout heart. I think he's a legitimately brave fighter and I think that's connected to the national pride he carries with him about being a Puerto Rican champion and all the history that goes with that. It helps buoy him through tough times the same way it did with Trinidad when he would get dropped or hurt in a fight.

"Miguel Cotto is a game, game, tough guy. Sometimes he makes himself a little accomodating and doesn't throw from secure places and that leaves him open to get caught, which makes him vulnerable. But he's legitimately committed to being a world champion. It means a lot to him. It's part of the essence of what makes him tick.

"He comes to pressure you and throw punches but he's not just a walk-to-you guy. He's cognizant of the fact he shouldn't get hit. I've seen him try to switch up and box the best he can and that shows me he's thoughtful in there. He understands there's got to be more to this than offense. So he's aggressive but he tries to be as clever about his aggressiveness as possible. That will help him against bigger guys.

"He's not a monster puncher but he has the attitude that he can make body punching work for him. School's still out on whether his power will carry in the welterweight division. I'm not sold yet that he's a full welterweight. That's why I would like to see him and Margarito. You get answers there. Is Margarito legitimate against an agrressive type guy who can go to the body? Can Cotto handle a big welterweight? Time will tell if the size of a full blown welterweight is a problem for him but he'll have success at 147. Blind success with anybody? I'm not ready to say that. But I know this. Miguel Cotto is a fighter.''

How good a welterweight fighter we'll have to wait a little longer to find out. But, one way or another, not much longer.

"Miguel Cotto is a game, game, tough guy. Sometimes he makes himself a little accommodating and doesn't throw from secure places and that leaves him open to get caught, which makes him vulnerable. But he's legitimately committed to being a world champion. It means a lot to him. It's part of the essence of what makes him tick."