Commissioner Bud Selig on retiring in 21 months: 'You can believe it.' (USATSI)

Baseball commissioner Bud Selig seemingly has planned to step down, retire or vacate his job almost since he took office back in 1992. But this time, he is much more emphatic about his retirement pronouncements, even to the point of believability.

“You can believe it,’’ Selig said, pretty convincingly, by phone.

There are several reasons his public proclamations are more believable this time, but one previously unknown nugget that’s come to light adds to its credence. According to two ownership sources, Selig was actually offered a five-year extension when he signed the two-year deal a year ago, and without hesitation he took the two instead. When the term expires, he’ll be 80, and word is he figured that was a nice round number.

Selig wouldn’t comment about the decision to take the much shorter deal. But he was firm on the phone about the next one, the call to retire in 21 months.

“I really am,’’ he said. “I know the owners are having a tough time with it … (But) I am serious.’’

It's no shock not everyone believes him considering how many times he’s changed his mind in the past. Despite his stronger statements, some baseball owners are still said to wonder whether Selig will really leave the job when his term expires Jan. 15, 2015 (it’s actually two weeks later than has been reported), and at this point that skepticism understandable.

They don’t necessarily believe him, and they don’t want to believe him. He’s said to still be fielding calls from ownership friends that are half doubt and half protest.

Many also wonder whether a replacement can be found that can garner the needed three-quarters vote.

 “There isn’t a man or woman alive who can get the 24 votes,’’ one owner said.

 But the evidence is mounting that they’ll need to find someone.

Selig, who was extended unanimously two years ago after then-Padres owner John Moores finally relented (he was upset at the time that a vote on prospective new owner Jeff Moorad was delayed, but felt better when made $200 million more after selling later), told the Associated Press Sports Editors of his plans the other day in New York. And he’s telling friends the same. After meeting with several skeptics in the ownership ranks recently, he confided to a buddy, “I’m done (when the contract ends).’’

Selig’s popularity among other owners is a large part of the reason he’s stayed this long, and if he changes his mind again, that’d be the reason. He’s been heard to say many times something along the lines of, “Well, if they feel that strongly.’’

It’s of little wonder they do.

The sport’s rise to become an $8-billion-plus industry (from $1.2 billion when Selig began in ’92), 21 years of labor peace (counting until through the end of the current CBA), 22 new ballparks and especially the through-the-roof franchise values are big reasons for that popularity among owners. The Dodgers sold for a remarkable $2.15 billion a year ago next week, and the small-market Padres for a just-as-remarkable $800 million a few months later.

 The other reason for Selig’s popularity is an uncanny ability to get along with a wildly divergent variety of owners over the years, from George Steinbrenner to all the small-market owners, as he once was.

Selig, who was reported to make about $18 million, understands he’s made retirement proclamations in the past. But this time is different, he said. “In the past I meant it. But I also wanted to do what was in the best interest of the sport,’’ he said.

His friends know this is the perfect job for him. His favorite things in the world are to talk about baseball and to talk with friends, and this is a job that allows him to do both, basically around the clock.

But he’s teaching a class at Marquette now and is set up to teach history at the University of Wisconsin when he retires. He also wants to write a book.

Others speculate he wouldn’t mind being inducted into the Baseball Hall of Fame, though he’s never expressed that desire publicly.

His own explanation for his decision is much simpler than that.

“I’ve done this for a long time, and I’m proud of what I’ve done,’’ Selig said.

“There’s a time to come. But there’s a time to go, and this is it.’’