Redskins quarterback Kirk Cousins, who is in line for a long-term contract this offseason, presents quite the conundrum. He’s second in the league in passing with 2,454 yards, but the offense he guides is just 15th in scoring. (Alex Brandon/Associated Press)

It’s strangely typical that Kirk Cousins, the quarterback who never can do enough, would have a career day during a game that ended in a tie. There is no better illustration of the inconclusiveness of his franchise record-breaking numbers than to watch him throw for a preposterous 458 yards and still leave you dissatisfied.

In the first half of this season, the Cousins conundrum has grown more complicated despite what the inflated statistics show. Actually, it’s because of those inflated statistics. Midway through a most crucial season of evaluation for both the quarterback and the team, this is becoming an unprecedented brain-buster.

A year ago, Cousins threw for 4,166 yards (a franchise record) and 29 touchdowns in his first season as an unquestioned NFL starter. The Washington Redskins weren’t sure how to value his meteoric rise, which included a superhuman second-half performance that propelled the team to the playoffs. So they placed the franchise tag on Cousins this season, a one-year, $19.95 million deal to buy time on figuring out a long-term contract.

This season, Cousins has been even more productive, at least in terms of yardage. He has thrown for 2,454 yards with 12 touchdowns, seven interceptions and a 93.1 passer rating. He has directed the league’s third-best passing offense. Washington also ranks third in total offense, racking up 410.2 yards per game.

And all of this means . . . what? The numbers look heavy, but for half a season, they have felt flimsy. Washington is just a middle-of-the-pack scoring team. Cousins still makes too many mistakes and squanders too many opportunities.

The Washington Post's Scott Allen and Keith McMillan break down the Redskins' Week 8 tie with the Bengals. (Thomas Johnson/The Washington Post)

Ask anyone — the Cousins supporters, critics or indifferent observers — about the kind of year he is having. No one would suggest that he is halfway through an all-time great campaign. Yet Cousins is on pace to throw for 4,908 yards in 2016. That would be the 13th-most prolific season in NFL history. The quarterbacks breathing that air are known by their last names: Manning (Peyton and Eli), Brees, Brady, Marino, Roethlisberger. The two members of the 4,900 Club who aren’t yet Hall of Fame-worthy are Matthew Stafford and Tony Romo, two stars in this era. And then there’s Cousins, if he keeps track.

Here’s where the Cousins conundrum is unprecedented: Name a quarterback in league history who crushed numerous franchise records in his first year as The Guy, only to increase his production the next year — to a historic level — only to remain a player who inspires moderate enthusiasm about his long-term future with his current team. You can’t name another quarterback. Teams have moved on from highly productive quarterbacks, but not at those lofty numbers.

Still, there are more layers to consider.

Barring injury or a dramatic change in Coach Jay Gruden’s pass-happy offense, Cousins is almost certain to reach 4,500 passing yards this season. That has happened only 48 times in NFL history. But Cousins is on pace for just 24 touchdown passes. Of those 48 quarterback performances of at least 4,500 passing yards, there have been just three instances in which a QB threw for fewer than 25 touchdowns.

This is how you build the case that Cousins is an empty stat collector. This is how you figure he is the creation of Gruden and an offensive staff that runs one of the most clever systems in the NFL. This is how you look at Washington’s poor red-zone performance this season and conclude that the quarterback doesn’t do enough when the passing windows are tighter and daring decision-making and moxie factor into performance.

“We have to finish drives and figure out ways,” Gruden said. “We have too many weapons and too many good players not to convert drives into touchdowns, and that’s something that we’ll address.”

Gruden has said that for weeks, and the emphasis hasn’t led to much progress. Defenses have challenged Washington. They have said, “Okay, you have an accurate quarterback and an array of weapons. We’ll take away DeSean Jackson deep, play soft coverage and challenge you to go 75 or 80 yards in 12 plays without making a mistake.” Washington can’t do it consistently. Cousins and the offense are great until they get within 20 yards of the end zone. Then come the mistakes.

Redskins reporter Master Tesfatsion breaks down Kirk Cousins's early-season struggles. (Thomas Johnson/The Washington Post)

More explosive plays would help alter things, too. But that isn’t the strength of Cousins or this offensive system. During the 27-27 tie against Cincinnati on Sunday, there was hope in this area. Cousins had two second-half touchdown passes of more than 20 yards. But can he do more of that?

The bottom line is, Washington needs to see even more out of Cousins before making a definitive decision about his future. And I’m not sure you’re going to see anything dramatically different. What’s Cousins going to do? Throw for 400 yards and three touchdowns per game in the second half of this season? It would help if the coaches worked harder toward building a consistent, functional running game to support him, which might lower his yardage totals but improve his overall efficiency. But most likely, this is what Cousins and the offense has become: Good enough to play cat-and-mouse games with defenses and collect yards. But when it comes to scoring — you know, the most important part of offensive football — this is still an average unit.

Washington is just 15th in points per game at 23.3. Cousins and Co. score five fewer points per game than New Orleans, which is its peer in yardage production. That’s almost a touchdown less than ideal. If Washington averaged 28 points, it wouldn’t have a 4-3-1 record. It probably would be 6-2, and there wouldn’t be as many questions about the validity of its winning record.

Yes, defense is still Washington’s biggest problem. I’m not here to blame Cousins. But this team was built to win with great offense while the defense remained under construction. The offense has to do more. It has to reflect its yards.

Cousins might have $50 million guaranteed riding on that improvement. A year ago, this is the point in which he took a huge leap. If he can do that again, he’ll get paid by the team that developed him.

If he can’t, General Manager Scot McCloughan and the front office might have to do something that no team in NFL history has done: Let a 4,500-yard quarterback hit the open market.