Floyd Mayweather shakes up boxing, signs six-fight deal with Showtime and CBS

Floyd Mayweather has signed a six-fight deal with Showtime/CBS, which is absolutely blockbuster news that changes the landscape of American boxing, and signals the true arrival of Showtime Sports as a direct and extremely serious competitor for HBO Sports, which has been the No. 1 boxing network in the States for decades.

The deal spans 30 months, and Mayweather will next fight on May 4, when he'll face Robert Guerrero for the WBC welterweight championship. That fight is official, though a proper press conference and all that has not happened yet.

This move cannot be oversold. This puts HBO's back to the wall in a major way, and is an incredible, downright shocking move from Mayweather, who has been an HBO loyalist over his career, and made himself a superstar via their "24/7" vehicle, which he helped launch in 2007. Since then, he has been, along with Manny Pacquiao, the face of boxing, and the face of HBO boxing specifically.

Leonard Ellerbe tells Dan Rafael that HBO made a substantial offer, but Showtime/CBS simply offered a lot more, saying HBO brought a knife to a gun fight.

The biggest pay-per-view star in the sport has jumped ship to the "B-team." They're not going to be the B-team anymore.