For the most part, highly rated classes translate to high winning percentages. Many of the exceptions have to do with playing in a conference that recruits extremely well. For example, Ole Miss is #21 in class ranks but only #8 in the SEC. Their on-field performance doesn't measure up to their classes. On the other side, there are programs like Boise (#76 in class ranks, #1 in win %), TCU (#61 in class ranks, #5 in win %) and Utah (#59 in class ranks, #9 in win %). But while their class ranks are low nationally, they're high for their respective conferences. Beyond that there are outliers like Notre Dame (14 in class ranks, #46 in win %) and Wisconsin (#36 in class ranks, #14 in win %). It seems like continuity of system has a pretty strong impact on win %, even if coaching changes don't necessarily matter.
http://collegefootball.rivals.com/content.asp?CID=1238729
http://collegefootball.rivals.com/content.asp?CID=1238729