In early 2007, Charley Casserly, after 18 seasons as an NFL general manager, returned to his draft studies. He consulted history, pored over stats and presented an unsurprising conclusion: The later the pick, the harder it is to stick.
In Casserly's 10-year study of round-by-round results, 75 percent of first-round selections became "successful" players, which he defined as starting within four years of being drafted. Second-rounders had a 50 percent chance of success. Third-rounders: 30 percent. Fourth-rounders: 25 percent. Seventh-rounders: 9 percent. It was an imperfect calculus of an imperfect science.
The Ravens enter Thursday's draft with seven of the top 135 picks for the first time in franchise history, and none more scrutinized than No. 6 overall: Offense or defense? Joey Bosa or DeForest Buckner? Laremy Tunsil or Ronnie Stanley? But in a predraft news conference this month, Ravens assistant general manager Eric DeCosta focused on Nos. 104, 130, 132 and 134, a quartet of picks separated from the first-rounder by two days, millions in guaranteed money and immense odds of NFL success.
"If we have a crystal ball, and we look back on this draft five years from now, we're going to say that this draft was either made or broken by the fourth-round picks," DeCosta said. "We've got four fourth-round picks, and we've got to nail them. We've got to get some starters with those fourth-round picks. Our challenge will be to get four starters with those picks, to nail those guys, because I know we're going to do that in the first three."
To find four starters with four fourth-round picks will indeed be a challenge, even for the Ravens. With Casserly's math, their odds are about 0.4 percent.
A four-player haul would be significant not only for the Ravens roster but also for its historical rarity. Since 1996, the Ravens' inaugural year in the league, only one team has drafted four players in the fourth round. In 2010, the Philadelphia Eagles took cornerback Trevard Lindley, linebacker Keenan Clayton, quarterback Mike Kafka and tight end Clay Harbor. Only Harbor is still in the NFL.
The draft is not without its late-round darlings, of course, but for every Richard Sherman (fifth round) or Antonio Brown (sixth round), there are dozens of players like Gino Gradkowski (fourth round), solid but unremarkable guys who contribute what they can, then move on — to another team, another league or another profession.
No team can prosper without production from its Gradkowskis, those overlooked and underappreciated mid- and late-round picks. Ten of the Ravens' Week 1 starters last season were taken after the third round or not at all; three led the Ravens in end-of-season statistics: seventh-rounder Justin Forsett (rushing yards), undrafted Kamar Aiken (receiving yards) and undrafted Justin Tucker (scoring).
The Ravens have nine total picks in this draft. Their extra fourth-rounders are from a trade with Denver (the 130th pick) and league-awarded compensatory picks (132 and 134). The fourth round is scheduled to begin at noon on Saturday, following Thursday's first round and Friday's second- and third rounds.
If DeCosta and general manager Ozzie Newsome hope to find a star in the fourth round, they might as well be panning for gold in the Gunpowder River. Of the 153 players taken in the round since 2012, only one, Atlanta Falcons running back Devonta Freeman, has been named to the Pro Bowl (Kirk Cousins, Lamar Miller and Martavis Bryant are other great values in that span). In the history of the franchise, the Ravens' lone fourth-round Pro Bowl selection played fullback (Le'Ron McClain); other accomplished picks have been a hard-nosed linebacker (Jarret Johnson), another starting fullback (Kyle Juszczyk) and a backup tight end (Dennis Pitta).
Luck is one factor; scouting is another. Market inefficiencies begin to present themselves after the first two or three rounds, and the best front offices can identify their potential value before others.
Defensive end Jared Allen was dominant at Idaho State but undervalued because of his Division I-AA (now Football Championship Subdivision) competition.
Running back/returner Darren Sproles finished fifth in Heisman Trophy voting in his junior season at Kansas State but stood just 5-foot-6.
Defensive tackle Geno Atkins was named first-team All-Southeastern Conference as a sophomore, but his sack totals and accolades at Georgia fell short each of the next two seasons.
Each was a fourth-round pick. Each became an All-Pro performer.
"I have found over some 30-some years of playing and studying in this league, there's two ways to evaluate. There's athletic measurables, and there's football measurables,'' ESPN NFL analyst Merrill Hoge said on a conference call this month.
"And oftentimes an athletic measurable can trump a football measurable in a decision-maker's eyes. That's where we believe that the mistakes are made. You've got to evaluate the football skill set and how does it translate. After you study a kid in college, you get a pretty good idea."
A review of possible fourth-round picks this year reveals what might as well be called Newton's third law of drafting: For every force attracting a team to a prospect, there can be an equal and opposite force repelling it.
Arizona inside linebacker Scooby Wright III won the Bronko Nagurski Trophy, Rotary Lombardi Award and Chuck Bednarik Award in 2014, acclaimed as the nation's best defender. But in 2015, he played in just three games because of injuries, and at the NFL scouting combine, he ran the 40-yard dash in a plodding 4.87 seconds.
Maryland defensive end Yannick Ngakoue finished tied for second in the country with 13 1/2 sacks last season but often was swallowed whole on running plays.
Rutgers wide receiver Leonte Carroo emerged as a physical, reliable possession receiver — one who also was arrested for simple assault under domestic violence in September. (The charges were dismissed when the alleged victim chose not to pursue the case.)
The Ravens' stockpile of fourth-round picks gives them the flexibility necessary to trade up, increasing their odds of drafting a future starter but also thinning the size of their draft class.
The Ravens do not have a crystal ball, as DeCosta noted. The right moves — trade up or stand pat, take a risk or go with the safe bet — have yet to become clear. Even if Newsome and DeCosta do land a winning draft class, it's no guarantee of a winning team.
In 2006, the Broncos took what former Denver and current Ravens outside linebacker Elvis Dumervil later called the "best draft class in Broncos history." After landing quarterback Jay Cutler and tight end Tony Scheffler, Denver's Ted Sundquist selected wide receiver Brandon Marshall and Dumervil in the fourth round, where the Ravens struck out on wide receiver Demetrius Williams (four career starts) and running back P.J. Daniels (one career game).
The Ravens made the playoffs in six of the next seven seasons, including a Super Bowl title in 2013. The Broncos, meanwhile, went 36-44 over the next five seasons and missed the postseason each year.
As for Sundquist, the Denver general manager who had found two Pro Bowl steals in the bargain bin? He was fired in 2008.