The NFL is the most mercurial of all of the major professional sports.
2012 has seen the introduction of five rookie starting quarterbacks, and each of them has made their mark in their own way.
A power ranking of the 32 starters at the halfway point of the season reveals some surprises regarding the rookies. It also demonstrates that some quarterbacks are as steady as north on a compass, even coming back from career-threatening surgeries.
Let's count them down, starting at No. 32.