There’s been a big market for wide receivers in the NFL this offseason. It’s a sign both of the evolving nature of the league to pass early and often and of these players hitting the market at the right time. Secondary receivers like Marvin Jones and Mohamed Sanu got paid like primary contributors as free agents, which started an adjustment for teams looking to hold onto receivers who are scheduled to hit free agency in the coming years.

First it was Allen Hurns and his extension in Jacksonville. Then it was stories about whether the Cowboys could afford a Terrance Williams extension. Most recently, it was Keenan Allen signing an extension with the San Diego Chargers.

Allen received a deal just over what the Jaguars gave Hurns. At its base, it’s a four-year extension for $45 million with incentives that could get the deal up to $49 million. There’s also $20 million guaranteed on the deal, which matches the Hurns contract. However, Allen's deal doesn’t touch those in the bottom of the top tier -- like the one given to T.Y. Hilton (five years for $65 million, $28 million guaranteed) -- and doesn't come close to the contracts Demaryius Thomas and Dez Bryant received last season. That's all before the class of 2014 gets new contracts with the likes of Sammy Watkins, Mike Evans, and Odell Beckham starting to get paid.

There are some who believe the jury should still be out on Allen’s abilities as a receiver, but even in his limited playing time during 2015, he showed an ability to carry a passing offense and promise as a future star.

Ups and Downs

If there’s a frustrating aspect of Allen’s game through his three-year career, it’s the inconsistent production in those seasons. By our Net Expected Points (NEP) metric, Allen’s had a season as one of the best receivers in the league, a season with well below-average production, and an injury-shortened, above-average year. That’s a lot of fluctuation in such a short amount of time. Here’s how those numbers look among the receivers with at least 32 targets in each season (two per game for a 16-game season).

As a reminder, NEP measures the number of expected points a player adds to his team's total over the course of a season.

The 2014 season stands out as disappointing, but there were signs during that year that a continuation at that level wasn’t to be expected. Indeed, Allen bounced back in 2015 before his season was cut short after eight games due to a lacerated kidney. While his per-target efficiency wasn’t near his stellar rookie year, Allen was seeing tremendous volume and accomplishing feats that placed him among the game’s best receivers.

High Volume

The San Diego Chargers were void of offensive weapons for much of the 2015 season. The running game was among the league’s worst -- 31st in Adjusted Rushing NEP per play -- and the quality of wide receivers outside of Allen was minimal. It was an offense that eventually gave Danny Woodhead over 100 targets because he was the best receiving option.

But before Allen was injured in the Week 8 game, the offense ran through him. He saw 89 targets through eight games, a 178-target pace over 16 games. That would have placed him as the fourth-most-targeted receiver in the league had he completed a full season.

Allen also wasn’t just targeted at that high pace; he was catching most of those passes coming his way. Allen had a catch rate of 75.2 percent, which was behind only the Seattle Seahawks’ Doug Baldwin for highest catch rate among receivers with at least 80 targets. Of the 49 receivers to see that many pass attempts thrown their way, Antonio Brown was the only receiver to also be above 70 percent with his mark of 70.5 percent.

Part of this was due to quick routes working the middle of the field, thanks to San Diego's impressive annual disintegration of the offensive line. But Allen was targeted all over the field and was able to bring in these passes with a remarkable ability to adjust to the ball wherever it was thrown. Like this:

Or this:

And this:

In two separate games last season, Allen caught at least 14 passes, something that’s only been done 59 times total since 1960. Allen became the eighth player to accomplish the feat twice and the third to do so in the same season. Antonio Brown also reached those same benchmarks later in the season. Justin Blackmon, Josh Gordon, and Roy Helu are the only other players to catch at least 14 passes in a game while under the age of 24; Allen did it twice. Jason Witten is the only player to catch 14 or more passes three times in a career.

Value in Allen's Youth

This brings us to Allen’s age. Heading into his fourth season in the NFL, Allen just turned 24 years old at the end of April. There have been eight players who have caught at least 200 passes before turning 24. Not only is Allen one of them, but he’s also the only one of the eight to not be drafted in the first round.

As young as he is, Allen will potentially be able to hit the market again at the age of 29. That could allow him to cash in on one more long-term deal before his play starts to decline. It also gives him a chance to consistently be one of the best receivers in the NFL by the time this current extension is up.

Allen has flashed the potential to be a superstar in this league, and the Chargers are paying him something less than that. But given his talent, Allen has the ability to outplay the value of his new contract and prove he belongs among those considered to be the best at the position.