"Upon further review" is a recurring segment in which This Given Sunday analyzes quirks and fascinating tidbits from the NFL's history books.
How best can we reveal to you how much the NFL has changed over the last half decade? Look no further than what the criteria was for a quarterback to be seen as "successful" decades ago in comparison to that same criteria in 2014.
Peyton Manning was the league's MVP in 2013. Here was his stat line:
68.3%, 5477 YDS, 8.3 YPA, 55 TD, 10 INT, 115.1 rating
Johnny Unitas was the league's first Associated Press MVP quarterback, back in 1959. Here was his stat line:
52.6%, 2899 YDS, 7.9 YPA, 32 TD, 14 INT, 92.0 rating
Among qualifying quarterbacks in 2013, that passer rating would place Unitas dead last, 0.2 percent behind Brandon Weeden. His rating would place him ninth, and only eight quarterbacks would have thrown more interceptions. Unitas averaged 241.6 yards per game, which would have ranked 15th in the NFL last year.
Here was Norm Van Brocklin's MVP stat line the next year:
53.9%, 2471 YDS, 24 TD, 17 INT, 8.7 YPA, 86.5 rating
In 1966, Bart Starr won the MVP despite throwing only 14 touchdown passes in 14 games. Manning reached that total less than four weeks into the 2013 campaign, and 25 quarterbacks finished with at least 14 touchdown strikes in total last season.
Unitas won the award with an 83.6 rating in 1967. That would have ranked 22nd in the NFL this past season, just behind Tampa Bay's Mike Glennon.
Even in the 1970s, the gap was comical. The average passer rating of that decade's five MVP quarterbacks was 93.5. Manning, Aaron Rodgers and Tom Brady have won five of the last six MVPs. In their MVP seasons, their average rating was 108.7.
The turning point might have been 1984, when Dan Marino shattered the NFL record with 48 touchdown passes while posting the highest passer rating of the modern era (to that point). Marino and Joe Montana were the first quarterbacks to consistently complete well over 60 percent of their passes as they dominated the 1980s. John Elway was the last MVP to throw fewer than 20 touchdown passes when he had only 19 in 1987, and from that point forward the explosion was on.
From the beginning of the MVP era in 1957 through 1983, only 18 quarterbacks threw 30 or more touchdown passes and only 64 completed more than 60 percent of their passes. Since then, in basically the same span, we've had 67 30-touchdown seasons and 387 quarterbacks have posted a completion percentage above the 60 plateau.
The emphasis on passing and rules restricting defenders, especially in coverage, explain a lot of this. But we truly are in a golden age of quarterbacks. Nine of the first 17 MVPs were quarterbacks (63 percent). Since 1974, 28 of the 40 MVPs have played quarterback (70 percent). That rate is 74 percent since 1987, 75 percent since 1994 and 86 percent since 2007.
Quarterbacks matter now more than ever, and they've never been better.