Coach Scott Frost had an emotional last day as UCF's head coach as the Knights took down Auburn in the Peach Bowl, finishing 13-0. (1:06)

Although UCF finished the season as the only undefeated FBS team after its 34-27 win over No. 7 Auburn in the Chick-fil-A Peach Bowl on Monday, College Football Playoff executive director Bill Hancock stood behind the selection committee's reasoning for ranking the Knights No. 12.

"The selection committee respected UCF," Hancock told ESPN on Tuesday. "After all, they're the group that put the Knights in the Peach Bowl. To qualify for the playoff, teams need to play tough schedules against good teams -- that is the way for all teams to stand out and be ranked high by the committee. UCF is an excellent team, but you still have to take into account who each team played and defeated during the regular season."

UCFcapped an undefeated season with a 34-27 victory over Auburn in the Chick-fil-A Peach Bowl. Kevin C. Cox/Getty Images

UCF played only one opponent all season that had been ranked by the committee, No. 20 Memphis, which the Knights beat 62-55 in double overtime in the AAC title game. The only Power 5 opponent UCF played during the regular season was 4-8 Maryland, which the Knights beat 38-10 in College Park. UCF was ranked behind five two-loss teams and one three-loss team in Auburn. Auburn's losses were to Clemson, LSU and Georgia in the SEC title game, but the Tigers also beat Alabama and Georgia during the regular season -- the two teams that are now playing for the national title.

After UCF's win over Auburn, outgoing coach Scott Frost said his team deserved a shot at the top four and said it took a "conscious effort" from the 13-member selection committee to keep the undefeated Knights out of its final top 10, which was released on Dec. 3.

"It wasn't right," said Frost, who is leaving UCF to be the coach at Nebraska, his alma mater. "I was watching [the selection show] every week, the committee sitting in a room and deciding that this two-loss team must be better than UCF because UCF is in the American, or this three-loss team must be better than UCF.

"It looked like a conscious effort to me to make sure that they didn't have a problem if they put us too high and a couple teams ahead of us lost. And oh no, now we have to put them in a playoff? But we just beat [Auburn], that beat two playoff teams and lost to another one by six points, and we beat them by seven."

On Monday, the Knights doubled down on their quest for CFP respect with a tweet declaring:

When asked if he had any regrets about the committee's final ranking following UCF's undefeated run, selection committee chair Kirby Hocutt said, "no, absolutely not."

"I strongly believe the selection committee got it right this season," Hocutt said. "I don't think you can sit back and speculate or second-guess or play the what-if game after the bowl season. That's for fans to do and I know fans enjoy that conversation, but is it fair? I don't believe so because we are basing our rankings on the 12 regular season games, and the conference championship games are played, and those are the 12 or 13 games we have in front of us to base our rankings on. ... Fans will forever disagree with the rankings, but as the selection committee, our goal is to rank the top 25 teams and get the four very best teams in the country for inclusion into the semifinals, and I would say mission accomplished."

The debate continued on Twitter after the Peach Bowl, where some fans argued that UCF didn't belong in the semifinals while others were quick to call for an expansion of the four-team playoff, especially after the semifinals produced two SEC teams in the national championship game.

"The CFP is all about teams, not conferences," Hancock said. "And these are two really great teams coming off landmark semifinals victories over tremendous opponents. The atmosphere in Atlanta will be truly something to behold. All I can say is, buckle up and enjoy."

Hancock also said there was no talk about expansion. "The commissioners and the presidents are very happy with the four-team playoff," he said.

When asked about the criticism that the committee's emphasis on strength of schedule will lock the Group of 5 out of the top four, Hancock disagreed, pointing to Houston's schedule in 2016. Under then-coach Tom Herman, the Cougars opened the season with a nationally televised win over No. 3 Oklahoma and beat a ranked Louisville team in November. Had Houston gone undefeated that year, it could have been at least considered for a top-five finish, but the Cougars stumbled, losing to Navy, SMU and Memphis. Hancock said he hears people say the system is unfair to the Group of 5 teams, "but I don't buy it."

"I don't believe it," he said. "Look no further than Houston. Everything was teed up for them, a good schedule, a good conference schedule, and I just disagree with those people."

Hancock said UCF "had an excellent season and played an inspired, great bowl game." As for whether UCF's success this year can help it and other Group of 5 programs in the future, though, Hancock said no because each season stands on its own merit.

"The committee starts all over every year and takes a fresh approach every season," he said. "It wouldn't be right for what's happened in the past to affect what happens this year. The committee respected UCF. They were ranked higher than any other team from that group. UCF was unfortunate not to be able to play Georgia Tech. You can what-if all day, but that certainly would've changed UCF's résumé for sure. Every game changes every résumé. That certainly wasn't their fault. They had a great season."