As some fret about the state of the quarterback position in the NFL, passing continues to become a bigger part of the game with each season. Consider: 2015 saw the league set records for completions, attempts, completion percentage, passing yards and passing touchdowns while simultaneously posting the lowest interception rate in league history; 61.5 percent of plays from scrimmage were of the passing variety in 2015, and that doesn't even include scrambles on would-be passes. That, too, is a league record.

It's easy to gain a sense of how good and bad relative passers look if you focus on the extremes. It's hard to imagine anybody playing the position in the history of football as well as Aaron Rodgers has during his peak over the past few years. The numbers for legends like Peyton Manning and Tom Brady have been unprecedented during their peak seasons. On the flipside, the disastrous returns of starting somebody like Johnny Manziel or Matt Cassel are as obvious and familiar as ever. When you're on the bottom end, you're the one lamenting how there just aren't enough quarterbacks; when the incredible quarterbacks look so great, the stragglers at the bottom look even worse than they have before.

The best baseline for quarterback play, though, is looking at the average passer. It's one thing to try to figure out what an average quarterback looks like among passers in 2015, but it's even tougher to put into context with other quarterbacks from the past. It's also a valuable piece of information to have when evaluating whether your favorite team has somebody it should be happy with or a passer it should attempt to improve upon in the years to come.

So let's run through some key categories and put "average" into context. There are a few statistics for which we don't have historical data. One is QBR; the 16th-best passer by QBR this year was Tennessee's Marcus Mariota, at 61.0. QBR is a rate statistic; in terms of cumulative impact, the 16th-best passer by Expected Points Added (EPA) was Jay Cutler of the Bears. The average quarterback throws his typical pass 8.26 yards in the air (Ryan Tannehill) and gets 5.38 yards after the catch from his receivers (Derek Carr). And without salary data, here's a good space to note that the 16th-highest paid quarterback in terms of cap hit was Sam Bradford, who was earning $12.8 million from the Eagles. The 16th-highest actual base salary was Robert Griffin's $3.3 million.

For all the other statistical categories, though, there is historical information for comparison. I'll run through each of those metrics below. In each case, I've chosen the 14th-best quarterback from 1985 (from a 28-team league), the 15th-best quarterback from 1995 (from a 30-team league) and the 16th-best quarterback from both 2005 and this past season (with the league at 32 teams). For the rate statistics, I'll only be including qualifying quarterbacks.

Let's start with a simple question of volume and move forward from there:

Attempts

1985: Mike Pagel, Colts (393 attempts)

1995: Dave Brown, Giants (456 attempts)

2005: Aaron Brooks, Saints (431 attempts)

2015: Cam Newton, Panthers (496 attempts)

Our first comparison typifies just how much harder the workload is for quarterbacks these days. Newton is the starting quarterback on a 15-1 team that loves to run the football when things are close, let alone late in blowouts. Even during his likely MVP season this year, Cam has been plastered with the reputation that he doesn't need to throw -- that the Panthers make it easy for him given Newton's supporting cast. That seems bizarre when Newton's No. 1 wideout is comfortably Ted Ginn, but whatever works.

Cam Newton leads an offense that is often characterized as a run-focused attack. Twenty years ago, it would have been pass-happy. Crystal LoGiudice/USA TODAY Sports

Even given those circumstances, Newton throws a lot more than his predecessors (a whopping 26 percent more than Pagel did in 1985, actually). Newton's 496 attempts would have been the fifth-highest total in the league in 1985. Now, it's mundane to throw the ball 31 times per game.

Completion Percentage

1985: Lynn Dickey, Packers (54.8 percent)

1995: Stan Humphries, Chargers (59.0 percent)

2005: Jake Plummer, Broncos (60.7 percent)

2015: Tyrod Taylor, Bills (63.7 percent)

Again, this is an example of a quarterback who isn't regarded as particularly accurate. Taylor completed 57.2 percent of his passes in college and was 19-of-35 in his professional career before catching on with the Bills and winning the starting job in training camp this preseason. Taylor isn't significantly more accurate than passers from the past, but the combination of an intensive screen game and reinforced rules barring defensive backs from disrupting opposing routes have made it easier to complete passes than ever before.

Taylor threw 131 passes within five yards of the line of scrimmage -- which isn't even that many; that was 25th in the league. Eli Manning threw a whopping 275 of those same pass attempts. Kirk Cousins went 202-for-268 on those throws, completing 75.1 percent of his attempts. That was the biggest reason why Cousins led the league in completion percentage (69.1 percent) this year.

The spike in completion percentage is probably the second-biggest difference between quarterbacks of the past and the passers of the present. Taylor's 63.7 percent mark would have led the league by more than two percentage points in 1985.

The guy who led the league at 61.3 percent? Some guy named Montana, whose third wideout that year was a rookie first-rounder out of Mississippi Valley State.

Yards Per Attempt

1985: Ron Jaworski, Eagles (7.1 ypa)

1995: Jeff Hostetler, Raiders (7.0 ypa)

2005: Josh McCown, Cardinals (6.8 ypa)

2015: Matthew Stafford, Lions (7.2 ypa)

There aren't numbers for the typical pass distance in the air for years past, but it's generally accepted that teams are throwing shorter passes than they ever have before. So while teams are getting all kinds of yardage throwing the football, that comes more from volume and increased completion percentage than it does from efficiency.

Yards per attempt is one of the only QB stats that doesn't look almost dramatically different now than it did 30 years ago. Focus on Sport/Getty Images

There's an interesting point to be made here between how the league evaluates skills and actually uses them. Stafford has arguably the league's best arm strength, a howitzer that many teams use as the example when they think about the prototypical quarterback. His average pass traveled 6.4 yards in the air this year, which was 34th in the league. There's nothing wrong with using your Bugatti to run errands within a half-mile of your house -- you will get there faster -- but it does defeat the purpose a little bit.

Sack Rate

1985: Bernie Kosar, Browns (7.1 percent)

1995: Steve Young, 49ers (5.3 percent)

2005: Josh McCown, Cardinals (6.3 percent)

2015: Derek Carr, Raiders (5.1 percent)

The other benefit of throwing shorter passes is that it's harder to get your quarterback sacked; ask the Chiefs how close they ever got to Tom Brady on Saturday. The sort of crazy sack rates from the past are now all but gone. Eight different quarterbacks posted double-digit sack rates in 1985, with Dieter Brock of the Rams at a staggering 12.3 percent. Even in 2005, David Carr -- Derek's brother, of course -- was sacked on 13.8 percent of his dropbacks behind a porous Texans offensive line.

This year, the only quarterback in double digits was Colin Kaepernick, at 10.3 percent in a small sample.

Interception Rate

1985: John Elway, Broncos (3.8 percent)

1995: Vinny Testaverde, Buccaneers (2.6 percent)

2005: Gus Frerotte, Dolphins (2.6 percent)

2015: Kirk Cousins, Washington (2.0 percent)

Here's the biggest difference between quarterbacks of the past and passers today: Interceptions have all but dried up. In the '70s, quarterbacks threw picks on 5.3 percent of their pass attempts. That's down nearly 50 percent by the time we get to this decade, with quarterbacks throwing picks on 2.7 percent of their passes since 2010.

This is where the changes that have occurred to the game over the last 40 years all manifest themselves most obviously. Quarterbacks are getting the ball out quicker and throwing shorter passes with smarter schemes to receivers who can't be covered as tightly for fear of penalties. The old saying about how only three things can happen with a pass and two of them are bad was always dumb, but it's even stupider now, as the league's interception rate draws closer and closer to the rate of lost fumbles on running plays (0.8 percent).

This is a passing league, and that isn't changing.

Touchdown-to-Interception Ratio

1985: Phil Simms, Giants (22 touchdowns, 20 INTs, 1.10 ratio)

1995: Chris Chandler, Oilers (17 touchdowns, 10 INTs, 1.70 ratio)

2005: Steve McNair, Titans (16 touchdowns, 11 INTs, 1.45 ratio)

2015: Philip Rivers, Chargers (29 touchdowns, 13 INTs, 2.23 ratio)

Again, this is an enormous spike driven by the decline in interceptions. What was acceptable 30 years ago -- what seemed effective even 10 years ago -- is fundamentally different now. There were only seven qualifying quarterbacks in the NFL who threw two touchdowns for every pick in 2005. This year, there were 18.

Passer Rating

1985: Eric Hipple, Lions (73.6 rating)

1995: Mark Brunell, Jaguars (82.6 rating)

2005: Donovan McNabb, Eagles (85.0 rating)

2015: Jay Cutler, Bears (92.3 rating)

Let's finish up with the oft-derided passer rating, a stat built for quarterbacks from another era that bears little resemblance to the game we play here in 2015. Passer rating weights touchdowns as nearly as valuable as interceptions, which is obviously insane; a two-yard touchdown pass shouldn't be treated similarly to an interception inside your own 20-yard line, but because people used passer rating long enough, it became a number people vaguely became familiar with.

The scale for passer rating, again, is totally different. In 1985, the worst qualifying quarterback was Vince Ferragamo of the Bills, who posted a 50.5 passer rating. (Fortunately for Bills fans, Jim Kelly showed up the following year.) This year, the worst passer rating in the league was Peyton Manning's 67.9 figure. Nine different quarterbacks, including Cousins, Taylor and Stafford, all posted passer ratings better than Ken O'Brien's league-leading mark of 96.2. What seemed good 30 years ago doesn't remotely apply anymore.

What was great in the past might only be acceptable today.

Look at the players who have come up in the 2015 rankings as an "average" quarterback: Stafford. Cousins. Cutler. Carr. Teams treasure these guys as franchise quarterbacks, either in the process of developing or having fully realized their potential. And in some ways, they are, but how valuable is average? Is it worth Stafford's megadeal, which might have cost the Lions Ndamukong Suh and a realistic shot at managing their cap effectively? Cutler's deal, which the Bears would have dumped for free if they could have last offseason? Or the deal Cousins is about to get from Washington if the two sides can come to terms? What seemed excellent even 20 years ago is mere competence today.