DALLAS -- The Big 12 will formally explore adding two or four teams, the league's presidents decided unanimously on Tuesday.

The partners don't matter; the math does.

That's the Cliff's Notes version of why the Big 12 pulled an apparent about-face Tuesday when it announced a formal exploration of expanding the conference.

While nothing is assured, Big 12 Board of Directors chairman David Boren indicated it is more likely than not the league expands as it will begin to "actively evaluate" schools that previously showed interest in joining the conference.

A bang-up presentation by Big 12 television consultants Bevilacqua Helfant Ventures and Navigate Research changed hearts and minds in a conference that had indicated expansion was all but dead.

The same conclusions supplied to the Big 12 in early May apply: Any number of teams added to the 10-team league makes it mathematically more likely it will be in the College Football Playoff each year.

Research from Navigate showed that, in any given year, the Big 12 -- as currently constructed -- had a 62 percent chance of reaching the CFP. That number goes up to as much as 77 percent with expansion.

The best route, mathematically, for the Big 12 to survive and thrive seems to be adding teams -- any teams.

"They were really good presentations," Big 12 commissioner Bob Bowlsby told CBS Sports. "It's really hard to get presidents and chancellors to be fully focused. We had a really good six-hour session.

"I don't know if we're going to add members, but we've taken another step."

Boren started this whole process 15 months ago when he all but demanded expansion for a league he said was "psychologically disadvantaged."

"It's a statement from the board we want to move forward [with expansion]," Oklahoma's president said during a conference call on Tuesday.

"I would say, yes, it's a forward step, it's a positive step. ... It's not a definite decision but there is momentum for the board to very seriously consider this possibility."

A 15-month exploratory process now has focus. Bowlsby will take the next the few months to go on what amounts to a Big 12 Over America Tour.

Who wants in?

The process could be a sideshow while the main event -- the college football season -- plays out. Boren previously said 25 schools had contacted the conference about getting in.

For now, the usual suspects have renewed hope -- BYU, Cincinnati, Colorado State, Houston, Memphis, UCF and UConn. An educated guess on the top two at this point?

BYU and an American Athletic Conference team.

"What, there's going to be beauty pageant to see who they select?," one industry observer said. "It's like 'The Bachelor.' I've never heard of it being done this way."

What could emerge is a bidding war to see who will take less. Any new members would be phased in to the Big 12, taking something less than a full revenue share for a period of years.

The existing members would pocket the rest until those schools get full shares.

"Let's just say it's a sellers market," Bowlsby said. "There aren't very many of us [Power Five conferences]."

The industry was abuzz Tuesday night with this unlikely outcome. As recent as last weekend, the odds of both the ACC adding a network -- which reportedly happened Monday -- and the Big 12 adding teams seemed small.

But the rights fees money that once seemed to have dried up is still flowing. The Big 12 would exercise a clause in its contract that guarantees any new members receive pro rata -- an equal share as current members. ESPN and Fox agreed to the clause when the contract was negotiated in 2012.

As of now, the winners -- er, expansion schools -- would get an automatic annual revenue increase to approximately $30 million per year.

The Big 12's payout increases to $35 million next year and $43 million at the end of the football deal in 2024, according to a source.

"We intend to exercise the full prerogative of what we negotiated," Bowlsby said. "I don't think we have to make apologies for stipulations we both agreed to."

Don't expect ESPN and Fox to extend the current deal, which has eight years to run, according to a source. It's in their best interests to see how viewers react to, say, watching Cincinnati and Kansas State.

Any new teams would likely be folded into the Big 12 in time for the 2018 season. By that time, the current deal would only run for six more years.

Bowlsby added that football-only members are possible but not likely.

While those consultants may have hit it out of the park, there is speculation that recent Big Ten and ACC deals influenced the Big 12's change of heart.

ESPN recently stepped up to pay the Big Ten $190 million per year for half of its rights through 2022.

On Monday, the ACC reached a deal with ESPN to launch a long-speculated standalone network. The ACC's grant of rights now extends through the 2036 season. That agreement essentially binds the teams together. If Notre Dame joins a conference for football in the next 20 season, it will be contractually obligated to join the ACC.

"It indicates that we live in a very fast-changing world...," Boren said. "We felt the need to receive at update from our consultants, including their best advice on what the impact of any ACC agreement ... might have on our conference."

With the landscape changing around it, why shouldn't the Big 12 take advantage of that clause? The conference could get it as much as $1 billion over the final eight years of its TV deal if it adds four teams.

"It's about more than just invoking the contract," Bowlsby said. "If we're going to add somebody there has to be good synergy, somebody on an upward trend."

But why, wondered one industry source, would you "water down your league." There's a reason the Power Five conferences emerged out of the last round of realignment.

They are the best collection of schools, the ones for which the networks will pony up to own their television and streaming rights.

"There's several teams in the AAC and Mountain West that were BCS teams just five years ago," Bowlsby said. "Those are just monickers."

He was referring to the likes of Boise State, Cincinnati, UCF and UConn, which either went to BCS bowls and/or were in previous BCS automatic qualifier conferences.

With expansion, Big 12 football almost assuredly gets worse. It doesn't care.

Big 12 expansion also has the smell of the Big Ten's expansion to Rutgers and Maryland. That was a fall-back move after commissioner Jim Delany failed in his attempt to get some combination of Georgia Tech, North Carolina and Virginia from the ACC.

But Rutgers and Maryland at least provided programming for the Big Ten Network. The Big 12 has already said it isn't doing a network.

Until this point, expansion was merely a discussion point.

That has changed. Boren expressed in June 2015 his desire for a conference network, a conference championship game and expansion.

He may get two out of three. The conference already reinstated a championship game beginning in 2017.

The league has played with 10 teams since the 2011 season after losing Colorado, Missouri, Nebraska and Texas A&M in the last round of conference realignment.

No timeline was given for commissioner Bowlsby's re-visiting of expansion. He did say the process could extend to the board's October meeting.

Oklahoma athletic director Joe Castiglione told CBS Sports earlier this month that expansion was dead, "at this time."

It may time for a very public resurrection.