Greatness is defined in so many different ways. Statistical production, individual awards, team success, longevity, supporting cast, raw talent and athletic ability all factor heavily in determining overall greatness. Sometimes, you simply know greatness when you see it.

So all factors were considered when trying to determine who the greatest quarterbacks of the BCS era have been. Here are the Top 50 signal callers since the BCS was implemented in 1998:

* - active, ** - not all seasons played in BCS era

Heisman Trophy trends finally appear to be changing. Defensive players are getting invited to New York City with increased regularity as one player from that side of the ball has been a finalist in three of the last four seasons. The age stigma has fallen by the wayside as well with Tim Tebow and Johnny Manziel each winning the award in just their second seasons on campus.

With spring practice underway across college football, most of interest will focus on quarterback battles or incoming freshmen that enrolled early to get a jumpstart on making an impact for 2013.

With spring practice underway for many college football teams, the countdown to the 2013 season has officially started. With preseason predictions right around the corner, it’s never too early to start thinking about which players might be the next breakout stars.

USC was billed as a national title contender last season but finished with a disappointing 7-6 mark and ended the year with a three-game losing streak. The Trojans are still under NCAA sanctions, so coach Lane Kiffin doesn’t have a full complement of players.

Coming off a season where eight teams made bowl appearances, along with the rise of Stanford and Oregon into annual top-five status, the arrow on the Pac-12’s future is clearly pointing up.

Each year a unique set of prospects enters the professional ranks with a chance to make an immediate impact on the country's most powerful sport. The 2013 NFL Draft, held April 25-27, won’t be any different. Guards and centers generally don't go very high in the draft as good ones can be found in the mid-to-late rounds. Two guards were taken a year ago in the first round — No. 24 and No. 27 overall — and no centers. The 2013 interior linemen class features one of the best guards scouts have seen in years and it means more than two inside blockers could go in the first round.

Each year a unique set of wide receiver prospects enters the professional ranks with a chance to make an immediate impact on the country's most powerful sport. The 2013 NFL Draft, held April 25-27, won’t be any different. This group will feature freaks of nature who need to polish their game. It has lightning quick jitter-bugs who will dominate the open field from the slot position. And it has elite, big-framed, down-the-field vertical threats as well. Whatever offense your favorite team runs, there is a wide receiver in this draft for you.

The start of spring practice for all 125 college football teams is a chance to start fresh and forget the bad results that came along with 2012. For a handful of coaches, spring practice is also the first opportunity to turn around a program and save their job for 2014.

Each year a unique set of prospects enters the professional ranks with a chance to make an immediate impact on the country's most powerful sport. The 2013 NFL Draft, held April 25-27, won’t be any different.