US boxer Floyd Mayweather gestures to thWhen Bob Arum made a deal to take Manny Pacquiao to Showtime for a single fight with Shane Mosley in 2011, Ross Greenburg, largely regarded boxing’s most powerful person, was pressured into resigning from his post as president of HBO Sports after 33 years for failing to retain the broadcast rights to one of the sport’s biggest stars.

With Tuesday’s announcement by Leonard Ellerbe that Floyd Mayweather has signed a multi-fight deal with Showtime, new president Ken Hershman has lost his network’s biggest boxing asset to their biggest rival after only a single year on the job. Making matters especially bitter is that prior to his appointment as President of HBO Sports, Hershman spent nine years overseeing Showtime Sports, the second biggest boxing broadcaster. His hiring to run HBO’s sports programming was a surprise given his very public criticism of the network before he began working there.

As for the actual fights, Mayweather is scheduled to face Robert Guerrero, a multi-weight class champion who has won fifteen fights in a row, on May 4th as part of the new deal with Showtime. It will be the first of what could be six fights over the next 30 months. With exact financial details still unknown, the agreement is being called not only the biggest in boxing history, but also the largest for an individual athlete in all of sports.

According to Ellerbe, CEO of Mayweather Promotions, HBO made a great offer, but Showtime’s proposal was “substantially greater in every facet.”

HBO was outgunned. They came to a gun fight with a knife.

HBO Boxing released the following statement:

We made an aggressive and responsible pay-per-view offer. Now we move on. We are focused on the best boxing franchise in the television business. We are proud of the roster of  superstar fighters and emerging stars who are scheduled to appear on the multiple HBO platforms this year.

While we wait to see the fallout from today’s news, it can be said that the biggest pay-per-view star in sports has joined the number two network. The only question remaining is how much longer that ranking will last.