LAS VEGAS – Zab Judah didn’t have to ponder the question for even a moment before he replied because he not only knew the sad answer, he’d lived it.

“When I look back at my career I just feel like I cheated myself,’’ the former undisputed welterweight champion said. “I didn’t give myself a fair chance. But I know if I lose this fight it’s only because it wasn’t meant to be. I know I have the talent. If it doesn’t come out now, it’s not going to come out.’’

What Judah is hoping comes out this weekend is his vast storehouse of physical gifts – speed, reflexes, power, ring generalship and relentless desire. They are the tools of his trade and Judah possesses them in considerable supply. If he can harness them it would seem IBF No. 1 contender Joshua Clottey will be facing a considerable problem Saturday night at the Palms, the upscale Las Vegas casino resort where Judah and Clottey will fight over the vacant IBF welterweight title.

That title became available when Antonio Margarito willingly relinquished it for a chance to beat up Miguel Cotto, the reigning pound-for-pound champion and the WBA title holder at 147 pounds. In essence, Margarito was hoping for the same thing Judah is hoping for. He was hoping his talent would come out, which it did last Saturday night not more than a mile or two from where Judah will seek perhaps his final redemption in boxing.

What resulted that night was a bravura performance against Cotto, one in which Margarito stopped Cotto in the 11th round by twice forcing him to take a knee before he gave up his title and opened up a spot among the ranking welterweights that Judah once felt he would fill.

When Zab Judah first became undisputed champion three years ago by stopping Cory Spinks in a rematch to claim the WBA, WBC and IBF titles, it appeared he had finally fulfilled all the promise he had shown ever since his amateur days. Three months later he battered and tormented a challenger named Cosme Rivera in his first title defense and the boxing world was convinced he had found himself at last after a career of a lot of success but some despairingly poor performances when he found himself on the biggest stages.

But just as Judah appeared on the cusp of becoming a force in the welterweight division he was outworked by journeyman Carlos Baldomir in a fight that cost him the WBC and WBA titles and was beaten by Floyd Mayweather, Jr. in his next outing to sacrifice the IBF title as well. Worse, a near riot broke out that night after Judah hit Mayweather low and then behind the head, a scuffle that ultimately cost Judah $250,000 and resulted in a year suspension from boxing.

In his second fight back, Judah rocked Cotto several times and cut him badly but ended up being dropped four times (twice from low blows and twice from legitimately damaging punches) before he was stopped with 49 seconds left in the 11th round. It was a valiant night for Judah but one that ended in the same harsh way that four of his other title fights had – with him being beaten down.

That’s why at 30 and entering his 16th world title fight, Judah knows there is little room for error any more. This time he must fight to his potential and perhaps beyond it to fight off one of the hardest men in the division just to get himself back into the position of having his named mentioned with welterweights like Margarito, Cotto, Paul Williams, Shane Mosley and newly crowned WBC champion Andre Berto.

They are the bright lights of the division now while he remains a flicker who could become a flame but only if he doesn’t flame out against Clottey.

It wasn’t ever supposed to be this way for Zab Judah (36-5, 25 KO) but he knows a lot of the reason his career has taken the twist and downhill routes that it has are looking back at him from the mirror every morning.

“When I got stopped by Kostya Tszyu I was a young kid who felt I was unstoppable,’’ Judah recalled. “The first round was just so easy. I remember I told my Dad in the corner, ‘I got this easy.’ He told me, ‘This guy is dangerous. Don’t play with him.’ But I dropped my hands, got clipped, went down and the loss happened.

“I felt I won the first fight with Cory Spinks and against (Carlos) Baldomir I didn’t have a mark on me and he looked like he’d been in a train accident but he got the decision. Floyd fought a good strategic fight and he beat me. Cotto caught me at a vulnerable time. I was coming off a 17-month suspension (actually 12 but he had only one tune up before getting in with Cotto, which proved to be a miscalculation).

“I hadn’t earned any money in 17 months. They asked if I wanted to fight Cotto and I said, ‘For how much?’ I didn’t give myself a chance.’’

Perhaps because of the depth of his talent Judah rebounded from what became a devastating 11th round loss in which he rocked and cut Cotto early but ended up enduring a terrible beating. Somehow his promise and his name brought him one last title opportunity after two keep busy fights against fistic nonentities, a situation he concedes is far from the norm in boxing.

“I’ve seen a lot of great fighters get one opportunity and get crushed and they’re back on ESPN Friday Night Fights,’’ Judah said. “Some of my losses have been like good wins for me. I feel blessed that I’m still able to go and get a pay-per-view slot with Shane Mosley (a fight that did not come off because Judah sustained a deep gash in his arm following a training session) and then a fight on HBO (with Clottey). It’s a great opportunity for me.

“I know what it takes to become a world champion. This is a blessing. I call myself Lucky Lefty. When the fight with Shane came apart I didn’t slow down because I knew another opportunity would pop up.

“Clottey is a very strong fighter. He’s determined but I’m mentally stronger than him. I been around this for a long time. I know the difference between a ballroom fight and the Thomas and Mack Center (Las Vegas’ biggest venue). I’ve really prepared myself well for this opportunity.’’

Clottey, too, sees this as an opportunity. It is the kind that is as much personal as professional. Clottey has made it clear that he has nothing but disdain for Judah, with whom his camp had at least one pushing and shoving altercation four years ago inside (and out of) Gleason’s Gym in Brooklyn.

That incident remains seared in his soul, a moment he intends to remind Judah of Saturday night in a harsh way.

“I told him. ‘Stop harassing me! Fight me!’’ Clottey recalled. “I wanted to fight him but he wanted to pay me to be his sparring partner. I never agreed to spar with the top guys. Cotto tried to give me money to spar. Mosley gave me money to spar. I said, ‘No! I want to fight with you.’

“Zab wanted to fight me in the street. I know that’s how he is. I really want to fight him bad – Zab Judah! If he beats me, I will retire for one year.’’

That kind of animosity will spill out at the concert theatre at the Palms, a cozy atmosphere in which no seat is more then about 100 feet or so from the ring. It is a place that can turn a boxing ring into a cauldron, which in a sense it is for Judah because he knows there is no room left for another night in which he performs as less than what he believes he is.

“He’s never seen a fighter with my speed,’’ Judah said. “I feel like I’ve been in the ring with elite fighters. The only notch on Joshua’s belt is Margarito (to whom he lost a 12-round decision two years ago). There’s no style I haven’t seen.

“He’s a steady fighter but all the great fighters have gears. You run in one gear you burn out your clutch. I can start fast pace, I can have slow pace. I can slip, move, box, fight. This is like a new beginning for me.’’

Judah attributes some of the change he feels internally to maturity and some to having left Brooklyn to live in Las Vegas, a city where he says the pace is slower and life is “easier.’’ But he also insists his rejuvenation comes from knowing all the skills he has been blessed with have not deserted him despite the fact he’s lost his last three big fights and is 2-3 with a no contest in his last six trips to the arena.

Those nights are history now with results written indelibly in the record books. They cannot be changed but his career can be for this is a new day for Zab Judah, one he believes will not be a bright one for Joshua Clottey.

“Joshua Clottey is no push over,’’ Judah said. “He’ll try hard. He’s like a piece of metal. You have to keep chopping away at it. But I know the kind of fighter I am.

“I know what I brung to Cotto in those early rounds (when he wobbled him twice and cut him severely in the lip and over the eye). I see a lot of great fights out there but I turned 30 last year so I know there’s not too many opportunities left either.’’

Not too many but one big one on Saturday night to become a world champion once again. One Zab Judah insists he’s ready for because, well, how can it be any other way?

“I really prepared myself well for this opportunity,’’ Judah said. “We’re from two of the toughest boroughs in New York. I’m from Brooklyn and he’s from the Bronx (via Accra, Ghana where Clottey lived until five years ago). There’s a saying in New York – the Bronx makes it but Brooklyn takes it. I aint’ never seen the Bronx take anything but a beating.’’