Tonight at the Mandaly Bay Casino in Las Vegas Nevada, former three-division champ Shane Mosley 39-3 (35) will fight WBA and WBC Junior Middleweight champ Winky Wright 47-3 (25). This is the first fight for both men since their meeting last March. In their last fight, Wright won a 12 round unanimous decision over the 3-1 favored Mosley, becoming the first undisputed Junior Middleweight champion in 29 years.

This is a career defining fight and a must win for both fighters. For Wright, a loss to Mosley in the rematch will no doubt cause some to believe his win in their first fight was a fluke. Not to mention knock him out of the running for some potential huge pay days against either undisputed middleweight champion Bernard Hopkins or top contender Felix Trinidad.

For Mosley the stakes are much higher. A second consecutive defeat by Wright would just about end Mosley's days as a title contender, and he would have some difficult decisions in front of him. But more importantly, it could effect how Mosley's career is viewed through the eyes of history. It wasn't all that long ago that Mosley was on top of the boxing world and considered one of its best fighters.

Shane Mosley turned pro as a lightweight in 1993. While moving up the lightweight ranks Mosley demonstrated versatility and power. He could fight effectively moving forward, pressuring his opponent, or moving away and drawing them to him. Physically he was a beast and was too much for any other lightweight. In August of 1997, Mosley won a lopsided decision over undefeated IBF Lightweight champ Philp Holiday. Mosley made eight successful defenses of his Lightweight title, and not one challenger went the distance with him.

In June of 2000, Mosley won the WBC Welterweight title from Oscar De La Hoya in only his third fight as a welterweight. After out-boxing and out-fighting De La Hoya, Mosley was thought by some to be on his away to greatness. However, in his fourth title defense Mosley was upset by former amateur foe Vernon Forrest. Forrest put Mosley down twice in the second round and completely dominated him over twelve rounds, winning a unanimous decision to take his WBC Welterweight title.

Against Forrest, Mosley showed a championship caliber heart, but had no answers for his long jabs and straight right hands and uppercuts. Six months later Mosley failed to regain the title from Forrest in their rematch, losing another, although closer this time, unanimous decision. Seven months later he moved up to junior middleweight and fought Raul Marquez. The fight was stopped in the third round and declared No-contest due to a cut suffered by Marquez as a result of an accidental headbutt from Mosley.

In his next bout he won a unanimous decision over WBA and WBC Junior Middleweight champ Oscar De La Hoya. Although the decision over De La Hoya was seen as controversial, Mosley was once again considered one of boxing's elite fighters. The two defeats of De La Hoya offset the two loses to Forrest, leading most to rationalize that Forrest—due to his height and long reach—just matched up with Mosley, but Mosley was the better overall fighter.

Once again as Mosley was being showered with high praise, he ran into another tall and long armed challenger. Only this one was a southpaw and longed to finally be in a big spot against a marquee opponent. Winky Wright beat Mosley and took his title in much the same manner as Vernon Forrest took his welterweight title. Wright totally befuddled Mosley and did whatever he wanted in the bout, winning a one-sided decision to become the undisputed Junior Middleweight champ.

Just as in his two fights with Forrest, Mosley wasn't able to come up with a Plan-B against Wright, and it cost him the Junior Middleweight championship. In his last four fights he's 1-3. And despite having good boxing skills and outstanding hand speed, Mosley hasn't been able to find a way to beat a fighter that he is unable to overwhelm physically.

Against taller fighters who use their long jabs, Mosley has never shown the ability to slip and get underneath while working his way in. Instead he panics, and starts rushing his punches looking to set up a big right hand shot to either end the fight or turn it around. That might not be a bad strategy if his right hand had the range and power of former six-division champ, Thomas Hearns—but it doesn't.

Since losing to Wright eight months ago, Mosley's stock as a great fighter have taken a big hit. Now he is viewed by some as a good fighter who if forced back by a taller fighter is rendered helpless. One undeniable trait shared by mostly all great fighters is that they were able to change and adjust when ultimately confronted by an opponent who fights a style that, for whatever reason, causes them difficulty. This is something that Mosley has failed to do in three fights with two different opponents who match up favorably with him due to their height and reach.

Tonight against Winky Wright, Mosley will get another chance to see if he can adapt and adjust to a bigger fighter. In all honesty, this fight is a must win for Mosley. If he were to lose in the same fashion he did last time versus Wright, his career would be most remembered for not being able to overcome and adjust to fighters who matched up with him.

Shane has often said that he wants to be remembered as an all-time great fighter. He's won world titles at 135, 147, and 154. And he really should have four since he skipped 140 and went straight to 147 from 135. Those are great credentials. However, if he loses the rematch to Winky Wright tonight, there is a very good chance that he'll be remembered more for that than his three world titles. For Shane Mosley, there is more than just the junior middleweight title at stake tonight.

» Read Wright – Mosley II Fight Predictions from staff