What's sparked the rise of productive late-round wide receivers?

Geronimo Allison's big play in the Green Bay Packers' win over the Bengals last weekend had Aaron Rodgers thinking back to his initial impression of the second-year receiver.

"I remember the first day I watched him at training camp," Rodgers told reporters after that game. "I said, 'How the hell did this guy not get drafted?'"

Some people might be wondering the same about Minnesota Vikings receiver Adam Thielen, who ranks second in the NFL in receiving yards -- sandwiched between Pittsburgh Steelers star Antonio Brown (a sixth-round pick in 2010) and Vikings teammate Stefon Diggs (a fifth in 2015). Of the top 20 receivers in yards so far this season, seven were late-round (5-7) picks or undrafted.

Three or four games is a small sample, of course. One big game and you're on the list. (Allison followed up that 72-yard catch against the Bengals by playing all of 16 snaps Thursday against Chicago; he wasn't targeted.) First- and, to a lesser degree, second-round picks are a majority among the statistical leaders every season. And every position is going to generate hidden gems who end up being more productive than higher picks.

Still, fast starts by the likes of Thielen and Diggs and the ascension of Brown, Seattle's Doug Baldwin (undrafted in 2011) and others into difference-makers echoes the thrust of Rodgers' question: How do some future star receivers slip in the draft, even as NFL teams are spreading out and throwing the ball more than ever in recent years?

I asked a handful of NFL executives and scouts I trust about it this week. And while everything in the draft is case-by-case, the most common answer from a macro perspective was supply and demand.

Proliferation of spread offenses in college football means many schools now have four starting receivers instead of two, so more players are getting development and exposure. It's the position that generates by far the most reports and grades heading into the draft, to the point many teams have an extra column on the board during meetings to handle the spillover. "We go back through that receiver group over and over, trying to get guys off, because there's so many names," one NFL executive said.

Said a general manager: "Guys that used to be corners and safeties that are great athletes now are receivers in college. Back in the day, where there might have been like 15 [legitimate receiver prospects] in the draft, there's like 35 [now] that have draftable grades." The majority of guys who stay on the board end up clumped together in those late rounds, where teams often hone in on specific traits that fit their systems.

The number of receivers drafted has remained relatively static over the past two decades -- between 28 and 37 every year since 1998. So, if the talent pool has expanded even incrementally, the odds are better of hitting on a stud late in the draft or undrafted free agency.

There are some historical trends in the type of receivers that get pushed down (shorter guys, small-school players, etc.), but it's often about specific flags on the player.

Coming out of Central Michigan, Brown was a slender 5-foot-10 and ran a disappointing 4.47 40-yard dash at the NFL scouting combine. "Hard sell when [you] have 80 guys bigger and faster," one scout said.

People at Maryland "killed" Diggs, one former GM recalls, telling scouts his big freshman year went to his head. Or, as Vikings coach Mike Zimmer put it to me this week: "He had a reputation that was not real good."

Baldwin had a bad rap out of Stanford, too. Thielen played at Division II Minnesota State, which isn't exactly an NFL hotbed. San Francisco's Pierre Garcon (sixth round in 2008) played at Division III Mount Union. Kansas City's Tyreek Hill (fifth in 2016) had a disturbing domestic violence issue. Allison was an inconsistent route runner with inconsistent hands at Illinois who seemed tight getting in and out of breaks (in case you're still wondering, Aaron).

Sometimes, it's about being in the right place at the right time. Sometimes, it's about being a type of player one team values more than everyone else. (See: the long line of receivers who have thrived in New England.) Projecting football character is a big piece of the puzzle, too, and that's often the area scouts miss more so than projecting on-field traits. It's a credit to those who, one or way or another, overcome whatever the NFL thought was lacking to produce at the highest level.

The Five W's for Week 4

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WHO faces more scrutiny if his team falls to 0-4, Marvin Lewis or Hue Jackson? Clearly Lewis, who came to a conscious and mutual decision with the Bengals to not address his expiring contract before this season, a source with knowledge of those discussions said. (That'd be unusual anywhere else, but the Bengals are an unusual franchise and Lewis, 59, has been in this spot before). Remember, Lewis offered up a plan to let Jackson succeed him in Cincinnati -- just not immediately -- before Jackson bolted for Cleveland after the 2015 season. There were some people in the building who felt the change should've been made then. Lose to Jackson's rebuilding Browns on Sunday, and the heat will really be on Lewis publicly, even if the close relationship he has developed with management over 15 years makes it unlikely they'd consider an in-season change.

WHAT is Chiefs rookie sensation Kareem Hunt's biggest hurdle to continuing his amazing start? Health, probably. He's the first player ever to have a 50-plus yard touchdown from scrimmage in his first three NFL games -- answering the questions scouts had about his big-play ability -- and leads the league by far with 401 rushing yards on just 47 carries. (By comparison, fellow rookie Dalvin Cook ranks second with 288 yards, on 61 carries.) It'll be worth monitoring Hunt's workload going forward, considering the plan was to split time with Spencer Ware and wear-and-tear was one of the concerns that caused Hunt to slide to the third round. He had 855 touches at Toledo despite missing five games with injuries and two more because of a suspension in his sophomore and junior seasons. He played most of his senior year with a cast protecting a broken wrist. "I felt like there was a lot of miles already taken off his tires," said one scout who studied Hunt extensively. "They rode him. They rode him hard. Every year, he had something (injury-wise). You're hoping this guy can hang in there." The Redskins' second-ranked run defense gets the next crack at stopping him Sunday.

WHEN will the NFL get to the level of the NCAA and review all big hits in replay to determine if the player should be ejected? (from @ChristopherOkey) That type of system hasn't drawn any interest from the NFL competition committee, according to a source familiar with those discussions. Officials already have the power to eject, which was emphasized to them this offseason, but historically, they've erred on the side of leaving players in the game for "football plays" as opposed to punches, stomps, etc. Plays like Bears linebacker Danny Trevathan's dangerous shot to Packers receiver Davante Adams' head are rare (and already covered under the existing rules for hitting with the crown of the helmet). A replay system like college football's would lead to numerous delays. With only 46 players on game day, ejections have a big impact on personnel. And the idea of targeting means evaluating intent, which just isn't something the NFL wants to add to officials' plates.

WHERE does the Broncos' run of run defense end? They've held Melvin Gordon, Ezekiel Elliott and LeSean McCoy to 83 yards -- combined. Cornerback Aqib Talib told me last week he gets bored in meetings because they're going over run fits so much, but it's paying off. One year after finishing 28th against the run, they're No. 1 so far. Next up: the Raiders' Marshawn Lynch, who one executive was raving about after watching his tape this week. How does Lynch look at age 31? "Like he's 25," the exec said. Lynch is averaging only 3.9 yards on 36 carries, but signs of prime Beast Mode are there.

WHY could last week be the turning point in The Great Anthem Debate? Kneeling or sitting during the national anthem isn't the point, nor the long-term plan. Only about a handful of players were demonstrating in Week 2, before President Trump's inflammatory statement brought a widespread response - not only from players, but the people writing their checks. "The resources change when Donald Trump makes a statement, because it puts the owners in a pickle," Lions safety Glover Quin told me. "So, some of the things that you wanted to do, you've got the owners that'll back you up now. You can do different things, more things. You can actually get the whole team involved." Quin added the Lions have "some things in the works" and other teams likely do, too, shifting focus to finding solutions for social injustice and other issues players have spoken about instead of the method for raising awareness of them.

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