from wiki (i know, but stuff like this is usually legit even on wiki):
Passing for 5,000 yards is a rare achievement in the NFL. Dan Marino was the first player to reach the 5,000 mark when he set an NFL record with 5,084 yards passing in 1984.[1] Marino's record remained intact for over a decade after his retirement in 1999.[2] Peyton Manning currently holds the record with 5,477 passing yards in 2013. Drew Brees is the only NFL quarterback to reach 5,000 yards more than once.[3]
NFL players with 5,000 passing yards in a season[edit]
Quarterback Team Passing Yards Season
Dan Marino Miami Dolphins 5084 1984
Drew Brees New Orleans Saints 5069 2008
Drew Brees New Orleans Saints 5476 2011
Tom Brady New England Patriots 5235 2011
Matthew Stafford Detroit Lions 5038 2011
Drew Brees New Orleans Saints 5177 2012
Peyton Manning Denver Broncos 5477 2013
Drew Brees New Orleans Saints 5162 2013
NFL players with 4,000 passing yards in a season[edit]
4,000 yards passing in a season was once considered a very rare feat but has lost a bit of significance over the years. During the 14 game era, only Joe Namath passed for over 4,000 yards in a season with 4,007 yards passing in the 1967 AFL season. During the 1980s and 1990s, 4,000 yards became the standard for the league leaders in the NFL. Over the last decade, 4,000 yards has become almost commonplace in the NFL. In the 2012 season, eleven quarterbacks passed for over 4,000 yards.[8] Peyton Manning has had the most 4,000 yard seasons (13).[9]
I included the 4000 yard comments because they show how 4000 is no longer the magic mark, 5000 is, but also how meeting the mark of that time was a very good sign of a playoff team. the D needs to be there to win in the playoffs but 5000 yards by QB means a very good chance of making playoffs. that is the new standard. having only 1 stud WR reduces that chance greatly.