Per Mark Schlabach at ESPN.com:
More than ever before, a school’s position in the preseason rankings has a bearing on its chances of playing for the national championship at the end of the season. So even the preseason polls, which come out weeks before a game is even played, figure heavily in determining which teams will be ranked Nos. 1 and 2 in early December.
Evidence A: Since 1991, college football’s national championship has come from outside the top 10 of the preseason Associated Press top 25 poll only three times — Oklahoma started 19th in 2000, Ohio State was 13th in 2002 and LSU was 14th in 2003.
Evidence B: During the last 20 seasons, 13 teams have lost a game and still managed to finish the regular season ranked in the top two in the BCS standings or either poll of record. But only one of those teams — LSU in 2003 — was ranked lower than eighth in the preseason poll.
So if your favorite team is beginnig (sic) the 2007 season outside the top 10 in the AP or ESPN/USA Today coaches’ polls, you’d better hope for an undefeated season. Otherwise, your team has a very small chance of winning the national championship.
I’m not sure why this is so hard to understand. And, unless you go to a system that only permits conference champs to be eligible, it would affect a “plus-one” format as much as it does the BCS.