On Monday, we dug into the roster makeups of all 32 teams going into the 2014 season, focusing mostly on size (specifically, height). Today, another look at the players who step between the lines on Sundays, focusing primarily on length of career.

• It’s often said that it’s a young man’s game, but sometimes it helps to understand how, well, disposable NFL players are, as well as how finite a pro football career can be. Here’s an illustration: more than 21 percent of the players in the game are rookies (467). That’s more than any other class and at least three times more than any draft class after 2010.
• The total number of players from the 2012 draft class (324) is equal to the number who’ve had careers of at least seven years. That includes all the players from the ’96, ’98, ’99, ’01, ’02, ’03, ’04, ’05, ’06 and ’07 draft classes.
• The number of players in the league from the ’14, ’13 and ’12 draft classes is more than half of the total players in the league (52.3 percent).
• After the ’08 class, there are no draft classes with more than 100 players still in the league. After the ’05 class, there are none with more than 50.
• If you’re recruiting quarterbacks as clients, understand that not many make it to the second deal. There are 18 in the league from the ’14 draft class, 13 from ’13, 14 from ’12 and 10 from ’11. However, there are only five from ’10, four from ’09 and five from ’08. There are 29 total from all remaining draft classes beyond that.
• Strangely enough, linebackers seem to have the best shelf life. There are 40 from the ’11 class still active, which exceeds all other positions. Wide receivers is next with 31. No one else has more than 30.
• Offensive linemen seem to have a rather short shelf life. There are no offensive guards still active who entered the league before the 2005 draft. There are just four offensive linemen who entered the league before the 2004 draft.
• While we’re at it, there are no cornerbacks, defensive tackles, wide receivers, running backs, tackles or guards who entered the league before the 2003 draft class. It just goes to show that when the speed (corners, receivers, rushers) or the maneuverability (tackles, guards, defensive tackles) go, it’s pretty much sayonara. So if you’re a player, or hope to be some day, focus on your legs, speed and quickness.