How do you set up gameplans when the personnel changes from week to week? If you're Purdue in 2010, you don't.
I've often referred in the past to both standard downs and the first quarter as times when a team's gameplan is most evident. You see some teams thrive in these areas while struggling later in halves and on passing downs, when having playmakers seems more important than gameplanning. At the same time, if you have either epic turnover in personnel or suffer poor injury luck, your gameplan situations fall apart. Like they did for Purdue in 2010.
Largest Combined Drop in Standard Downs S&P+ and First Quarter S&P+ Rankings* (2006-10)
1. 2007 Notre Dame (-208 spots) (epic turnover)
2. 2007 Pittsburgh (-187)
3. 2009 Rice (-177) (epic turnover)
4. 2008 Washington (-159) (injuries)
5. 2008 Auburn (-155) (hilarious scheme change)
6. 2010 BYU (-148) (epic turnover)
7. 2008 Washington State (-143) (coaching change)
8. 2008 Central Florida (-138)
9. 2010 Texas (-136) (turnover)
10. 2009 Ball State (-130) (turnover and coaching change)
11. 2009 Nebraska (-130) (Joe Ganz was a magic man)
12. 2010 Purdue (-128) (hilariously epic injuries)
13. 2009 Rutgers (-123) (turnover)
14. 2010 Kansas (-122) (epic turnover and coaching change)
* - This just adds two changes in rankings together. In 2007, Notre Dame fell from 15th to 117th in Standard Downs S&P+ (102 spots) and from 13th to 119th in First Quarter S&P+ (106 spots), which is almost literally as far as you can fall. In comparison, Purdue's drop (42nd to 110th on Standard Downs, 15th to 75th in the first quarter) is nothing.
And for what it's worth...
Largest Combined Rise in Standard Downs S&P+ and First Quarter S&P+ Rankings (2006-10)
1. 2009 Auburn (+190)
2. 2009 Virginia Tech (+172)
3. 2008 Iowa (+170)
4. 2006 Pittsburgh (+155)
5. 2010 North Carolina (+150)
6. 2008 Stanford (+147)
7. 2006 Syracuse (+145)
8. 2006 Oregon State (+137)
9. 2008 UAB (+128)
10. 2007 Colorado State (+137)