Floyd Mayweather is the world's best fighter and will move closer to both prison and a place in boxing's history books when he fights Miguel Cotto at the MGM Grand in Las Vegas on Saturday.

Mayweather has to report to the county jail on June 1 to serve a sentence of 90 days for assaulting his girlfriend, but first he must try to win Cotto's WBA light-middleweight title and the vacant WBC "Diamond" version. The bizarre situation where the revenue from a Mayweather fight boosts the local economy to such an extent that he can both fight and serve prison time at his own convenience could only happen in Las Vegas.

It is the Mayweather show and that is understandable because he has generated obscene financial figures whenever he has fought during the last six years, which is actually not that often, with only eight fights since 2006. The breaks from the ring have allowed Mayweather to reach 42 fights unbeaten with a face free of blemishes and a fine ego. He recently phoned US President Barack Obama to ask if he wanted to enter the ring with him on the night. The president, mindful of Mayweather's power, is said to have made a diplomatic, face-saving refusal.

Cotto, however, is not simply a number in the opposite corner and appears to have rediscovered his love of the sport after a difficult period when he was stopped twice in the last five minutes of two savage and life-changing fights against Manny Pacquiao and Antonio Margarito.

"I still consider Miguel an unbeaten fighter," Mayweather said. "He was fighting at catch-weight in one and we all know what was going on in the other fight."

Mayweather was talking about the Pacquiao fight where Cotto was made to lose weight to secure the bout, while in the second case he was referring to the suspicion of illegality hovering over Margarito, who was suspended for having a banned substance on his bandages at a fight after beating Cotto. Last December Cotto gained sweet and brutal revenge when he stopped Margarito in their re-match.

"I have been told that this is the hardest I have ever trained and it feels like it," said Mayweather, who has impressed many observers at private sessions in the gym with his sparring and willingness to stand and fight.

"It will be toe-to-toe and I'm prepared for that and that is what a champion has to do.

"Miguel is a dangerous puncher and he has come back a new man, a hard man. I can tell from looking at him that he thinks he will win. There is no fear in Miguel Cotto. That's good, because there is no fear in me."

There is, as usual in a Mayweather fight, a hidden agenda regarding what happens in the ring on the night. Many in the boxing business will want to compare Saturday's result with the 12th round stoppage of Cotto by Pacquiao.

"I'm fighting Miguel Cotto and not the record books," said Mayweather, whose intransigent stance on a fight with Pacquiao means the pair are no closer over the split of the spoils than when troubled negotiations began in 2007.

On Saturday Cotto will make his opponent fight, that is inevitable, but Mayweather's edge has been his speed and ability to take risks at the right moment. The fight will most likely be more even and exciting than most of Mayweather's nights in the ring, before he gets the better of Cotto by about round 10. It will certainly be memorable and that is what people expect of the sport's biggest attraction.

o Mayweather v Cotto is live on BoxNation (SKY Channel 456/Virgin Channel 546).