CHICAGO -- A college football playoff is imminent, and a four-team model is preferred by the Big Ten. This much is clear.

But that's the easy part.

How are the four teams selected? And where will they play? Those are questions being weighed this week by the Big Ten's athletic directors, who are in the midst of a three-day summit in Chicago.

Ohio State's Gene Smith affirmed each of the league's ADs now favor a playoff. That means Michigan athletic director Dave Brandon, a longtime hold out on a playoff, has changed his stance on the issue at these meetings.

But Smith said determining which model is used to select the four playoff teams could complicate things more than the BCS ever did.

Gene Smith

Mark Hollis

"I think once you guys get into the reasoning of it, start looking at the history of some of this stuff, teams (ranked) three, four, five, six, you can’t put a piece of paper between those teams," Smith said Tuesday afternoon during a break between sessions.

"It’s just like the NCAA (basketball) tournament. Who’s left out? That’s what’s going to happen, and I worry about that."

While the details of a four-team playoff remain undetermined, there are a few principles upon which many of the Big Ten's athletic directors seem to agree.

Smith said he's "adamant" the playoff doesn't expand to eight or 16 teams, because it would damage the regular season. That sentiment was echoed by others.

"I think the most important thing in college football is the regular season," said Michigan State athletic director Mark Hollis. "I think anything that detracts away from that regular season is a disadvantage for university life, college football and just the gathering and engaging that we want those home games to have."

So how will the four teams be selected? Smith and Hollis said they favor a committee, similar to the body that selects the field for the basketball tournament. This was discussed "heavily" by the league ADs on Tuesday morning, Smith said.

He added he favors installing a selection committee because it's the surest way to account for the nuances that separate teams battling for a playoff spot.

"There's a part of me that feels you have to have a people element in there, particularly for (teams ranked) three, four, five, six," he said. "There's something to be said for looking at who teams play, and where.

So where would these games be played? The Big Ten seemed to be considering college campuses as semifinal hosts, but Hollis said that no longer is on the table.

Instead, the Big Ten has shifted its focus to including the bowls in the playoff structure. That also would preserve the importance of the Rose Bowl, which has been a priority of the league.

"For me, it's critical to keep the Rose Bowl in the equation," Hollis said. "There's a lot of historical value and there's a lot of future value to having the Rose Bowl connected with Michigan State, with Michigan, with the Big Ten Conference, and the home (game idea) takes that out."

Smith said he also has concerns of playing playoff games in cold weather, which seemingly would offer the Big Ten an advantage against Southern teams.

"Let’s say Ohio State is hosting, and it’s whatever the date may be -- January or December. Let’s say it’s 5 degrees. Is that right for the game? We’re not pro," Smith said. "I think a fast surface, good weather is important for the game. It’s important for the kids.

"The only thing I prefer now is we play in the bowl system. All the other stuff, I’m still spinning on where we’ll end up."

Big Ten commissioner Jim Delany recently drew some fire for saying he would like to see conference champions ranked among the top-six teams earn automatic bids into the playoff.

Hollis and Smith, though, said their preferred systems include either two or three automatic qualifiers who are conference champions, and one or two spots reserved for at-large bids.

It's clear the Big Ten athletic directors unanimously prefer a four-team playoff, but are a long way from firming up the details. They'll continue to hash it out through Wednesday, and Smith said he hopes to have things finished up by September.

Whatever system wins out, Smith knows it still won't be perfect.

"You have to have body guards after you're done selecting," he said.

Delany is scheduled to meet with the media Tuesday evening. Brandon will take his turn Wednesday.

Kyle Meinke covers Michigan football for AnnArbor.com. He can be reached at 734-623-2588, by email at kylemeinke@annarbor.com and followed on Twitter @kmeinke.