Manny Pacquiao is 54-4-2, including 2-0-1 against Juan Manuel Marquez (Chris Farina/Top Rank)

LAS VEGAS -- Manny Pacquiao and Juan Manuel Marquez have given boxing fans three fights for the ages, with almost unparalleled action, drama and suspense. Theirs ranks among the great trilogies in the sport's history, along with the likes of Erik Morales-Marco Antonio Barrera and Muhammad Ali-Joe Frazier.

Their first three fights have also been excruciatingly close. Personally, I scored fights one and two in favor of Marquez and had their third bout last year a draw at 114-114. Officially, the first match in 2004 was a split draw, while Pacquiao took a split decision in 2008 at Mandalay Bay and then won a majority decision last year at the MGM Grand.

Neither man has been happy about the way any of the three fights ended and have vowed to score a more definitive victory tonight.

[Related: Manny Pacquiao wants closure in Juan Manuel Marquez saga]

Pacquiao is better than a 3-1 favorite at the MGM Grand sports book, which is somewhat surprising given how close the first three bouts are.

Manny Pacquiao (R) prays for cancer patient John Rocero (center) and John's father, Roy (Kevin Iole)There's been a hard edge to Manny Pacquiao this week that is noticeably different from his recent fight week appearances. He's been intense and quiet as he prepares to meet Juan Manuel Marquez on Saturday at the MGM Grand Garden. He's not the loose and jovial guy he was prior to recent matches.

It's a big fight for Pacquiao, who has fought Marquez three times but who has yet to win one of them decisively.

Cancer patient John Rocero (L) presents a painting to Manny Pacquiao (Kevin Iole)But 18-year-old Pacquiao fan John Rocero faces a far more difficult fight: He has a Stage 4 brain tumor and is in a fight for his life.

It was hard to tell that on Thursday, though, as Rocero, a San Francisco Giants fan from Stockton, Calif., got the opportunity to meet his hero in person. Pacquiao was incredibly gracious to Rocero and his parents, Roy and Patricia, and spent about 20 minutes with them in a visit arranged by the Make-a-Wish Foundation.

Pacquiao signed several t-shirts and a painting of himself that John's sister had done. He also accepted a wrapped gift from the

Jim Brown (L) and Muhammad Ali talk on a movie set (AP file photo)Sports Illustrated's Chris Mannix wrote a wonderful profile of Top Rank chairman Bob Arum, who will turn 81 on Saturday. That's the same day that Arum promotes the fourth fight between Manny Pacquiao and Juan Manuel Marquez, one that is expected to generate at least 1 million pay-per-view sales.

Mannix's rollicking piece is filled with anecdotes from Arum's 46 years as one of boxing's leading promoters.

Jimmy Brown retired as the NFL's all-time leading rusher (AP file photo)The best, though, details the time that NFL great Jim Brown decided he wanted to fight then-heavyweight champion Muhammad Ali.

Brown is one of the greatest players in NFL history and is regarded by many as the finest athlete of the 20th century. In addition to being a dominant NFL player, Brown is also arguably the best lacrosse player who ever lived.

He also had a legendary reputation for his toughness. Given that Brown had introduced Arum to Ali, it was hard for Arum to say no without at least checking. Brown figured it was a slam dunk massive payday.

Brown had retired from the