After watching Chavis as DC for many, many years, you'll come to root for 3rd and short instead of 3rd and long. I never understood why (other than soft DB coverage), but he seems to be much better at stopping 3rd and 4 or less than he is at stopping 3rd and 5+.
I can literally remember watching games in the 2006-2008 seasons hoping for the opposing RB to gain 4 yards to get it to 3rd and 2, because I had much more faith that the D could pull off the 3rd down stop in those short yardage situations.