"I always think you have an advantage if you win," Cowell told reporters in a conference call Monday. "It's more fun to get the gold than the silver."
Cowell is doing double duty: mentoring Alex & Sierra as well as overseeing the Fox singing contest.
"For the show, because I produce the show, no disrespect to the other two [acts], I want the show to end with the best act winning," Cowell said.
They are not only the best act on "The X Factor" but the best act to come out of any singing show this season, Cowell said.
They will perform along with rocker Jeff Gutt and Latin singer Carlito Olivero at 8 p.m. Wednesday on WOFL-Channel 35.
Cowell acknowledged it has been an uneven season for "The X Factor." "I think the show started off OK," he said. "The four-chair section was terrific. The early live shows were OK. The last two weeks have been amazing. The show will be coming back next year."
But he later said the chances of the show coming back were good. "The X Factor" has run far behind "The Voice" in the ratings this fall.
For next season, Cowell hinted that he could have a different kind of role instead of serving as mentor. He later added that he was "in the middle of a presentation to Fox" about what the show could look like next season.
He said the show could possibly go to once a week rather than twice.
Would he keep the current judging panel?
"Probably not," he said.