NFL teams overpay for quarterbacks all the time. It's just the way the world works.

When you have someone who looks like he might be competent, you have to lock him up just in case he ends up being good. After all, few things can sour a fan base quite like trotting out journeyman after journeyman under center year after year.

So when Washington handed control over to Kirk Cousins, after numerous bouts of potential trade talks in the years prior, to start the 2015 season and he played well, it seemed as though Washington found their man.

But the team was reluctant to give him a long-term deal this offseason, deciding to use the franchise tag on him instead, in part because the team thinks they can find a younger quarterback in the next year or two who can perform at or close to Cousins' level at a cheaper price.

You know, kind of exactly like Cousins did this year by being the most cost-effective passer in the NFL by a landslide.

Good luck finding another Kirk Cousins, Washington.

Cousins' Career

Cousins has dropped back to pass (including sacks) 992 times in his four-year career. His 950 pass attempts have yielded 7,196 passing yards, 47 touchdowns (and a 4.9% touchdown rate) with 30 interceptions (3.2%), earning him an adjusted yards per attempt mark of 7.1 (and 7.7 if we look solely at 2014 and 2015).

Still, that 7.1 career mark makes him one of 17 quarterbacks to maintain an adjusted yards per attempt mark of at least 7.1 over at least 950 attempts since the merger. He's one of 16 to maintain those levels since 2000.

According to our Russell Wilson's 47.92%), he still stacks up well compared to his peer group at large.

Cousins' Success Rate ranks 19th among the 159 passers with at least 250 drop backs since 2000. This indicates that, while he's been a little more reliant on big plays to boost his NEP than some of the NFL's best passers (i.e. the top 12 in Passing NEP per drop back), he's been one of the best quarterbacks on a play-by-play basis in the last 15 years.

Further, in 2015, Cousins owned a Passing NEP per drop back of 0.24 over 569 drop backs (136.29 total). If you'll recall, that's actually more than his career mark of 128.28 because he was a below-zero passer in 2012, when he attempted 160 drop backs and earning a Passing NEP of -40.71.

You can look at that as a reason to question the authenticity of his recent success, but Cousins has just been good the past two seasons.

In 2014, he racked up 19.58 Passing NEP on 212 drop backs (0.09 per drop back). If we consider Cousins to be who he has been in 2014 and 2015 -- so 155.88 Passing NEP on 781 drop backs with a 50.45% Success Rate -- well, his marks stand up to some of the best passers in the game.

Conclusions

Yes, Cousins is thriving in a pass-happy league, one in which passing efficiency keeps climbing, so his metrics may not be quite as impressive as some of his older counterparts who endured through stingier secondaries.

But he still led Washington to the fourth-best schedule-adjusted passing offense in the NFL according to our metrics in 2015, and that shouldn't be overlooked.

The facts of the matter are that Cousins has posted some nearly unprecedented passing stats in his career and that there's a legitimate chance that he's significantly better than "replaceable."