This year’s NFL draft is shaping up to be a historic one with as many as five quarterback prospects tabbed as first-round selections. Only twice before — 1983 and 1999 — have at least that many passers been selected in the opening round.

That first class was sensational, featuring future Hall of Famers John Elway, Jim Kelly and Dan Marino alongside Todd Blackledge, Tony Eason and Ken O’Brien. The Class of ’99, on the other hand, didn’t fare as well. Donovan McNabb was an 11-year starter in the NFL but Tim Couch, the No. 1 overall pick, Akili Smith, Daunte Culpepper and Cade McNown were all disappointments.

And there is no guarantee that a higher pick will outperform a quarterback drafted later in the round. Since 1970, 24 quarterbacks produced more approximate value — Doug Drinen’s method that puts a single number on the seasonal value of a player at any position from any year — throughout their career than at least one QB chosen higher in the draft. There are, however, signs of success.

For example, Bill Connelly, creator of the S&P+ ratings which are based around the core concepts of efficiency, explosiveness, field position, finishing drives and turnovers, found that a quarterback’s success rate in college is his ceiling in the NFL. Success rate measures a team or player’s efficiency by determining whether a play on first down got 50 percent of necessary yardage to move the chains, 70 percent of necessary yardage on second down or 100 percent of necessary yardage on third and fourth down. Connelly looked at 38 quarterbacks who were drafted from an FBS school between 2010 and 2017 plus threw at least 300 passes in the NFL and found a success rate in excess of 49 percent was a prerequisite measure for success at the pro level.

For all of the hype surrounding this draft class, just two of the quarterbacks being considered as first-round selections meet or exceed that success-rate benchmark: Oklahoma’s Baker Mayfield and Sam Darnold from USC.

Baker Mayfield, Oklahoma
S&P+ success rate: 55 percent

Mayfield, at 6-foot-1, doesn’t have the height scouts drool over but neither did Russell Wilson (5-11) nor Drew Brees (6 feet) coming out of college. The 2017 Heisman Trophy winner and Big 12 offensive player of the year led the nation in pass efficiency (70 percent) with a record 41 touchdown passes and only five interceptions during the regular season. The game charters at Pro Football Focus, who have been analyzing college prospects since 2014, awarded Mayfield the best single-season PFF grades in each of the last two years, giving him three of the six highest-graded seasons overall. His 2017 passer rating in a clean pocket, per Sports Info Solutions, was the highest in the nation (143.4) and more than 21 points higher than Oklahoma State’s Mason Rudolph, who was second (122.0). Mayfield’s passer rating under pressure declined to just 117.4, a figure significantly higher than the rest of his peers in college football.

Sam Darnold, USC
S&P+ success rate: 52 percent

Darnold isn’t as accurate as Mayfield but he possesses all of the desired physical tools you like to see in a franchise quarterback in addition to a big arm, good mobility and a knack for extending plays. His 96 passing attempts out of the pocket in 2017 were the eighth most in the nation per Sports Info Solutions and his 91.5 passer rating was 32nd out of 153 quarterbacks with at least 20 attempts on the run. And he, like Mayfield, was an above-average passer when facing pressure (73.9 passer rating) last season and led all Division I quarterbacks with 1,178 yards passing in these situations.

Darnold also used his running backs as receivers, completing 37 of 44 throws (84 percent, 12th highest in the country in 2017) — not including shovel passes — for 423 yards and a touchdown to a player out of the backfield.

Lamar Jackson, Louisville
S&P+ success rate: 47 percent

Jackson’s completion rate under pressure at Louisville was only average (43 percent) and he did not find much success on deep passes, those traveling at least 20 yards downfield, despite such balls accounting for 18 percent (76 out of 430) of his throws. His completion rate on those throws was below average (29 percent compared to 32 percent for the nation). His biggest strength is on passes within nine yards of the line of scrimmage (67 percent competition rate), but even then he was still only slightly above average (66 percent). He does, however, provide an element in the running game that few can match.

Jackson carried the ball 232 times for Louisville last season, producing the sixth-most yards among all players (1,617) with the ninth-most rushing touchdowns (18). According to Sports Info Solutions he also averaged 4.1 yards per carry after contact, the 12th best rate among all players with at least 100 carries in 2017. Among quarterbacks, only Arizona’s Khalil Tate was better at moving the pile or creating space to run (4.3 yards per carry after contact).

Josh Rosen, UCLA
S&P+ success rate: 47 percent

Rosen’s footwork and mechanics are what you would expect out of a first-round pick, but his health is a major concern. The 2015 Pac-12 freshman of the year played just six games in 2016 because of a season-ending injury to his throwing shoulder and suffered two concussions during the 2017 campaign.

When on the field he was solid. He completed 63 percent of his passes when blitzed in 2017 but saw that decline to 48 percent against the conventional pass rush. In addition, Rosen completed just 40 percent of his passes when flushed from the pocket. The national average was 49 percent.

Flushed from the pocket in 2017 Completion rate Yards per attempt Passer rating
Josh Rosen 40% 3.3 53.2
Rest of NCAA QBs 49% 6.0 73.8

His arm strength, meanwhile, is decent — Rosen completed 16 of 46 passes (35 percent) thrown at least 20 yards past the line of scrimmage for 627 yards, six touchdowns and only two interceptions.

Josh Allen, Wyoming
S&P+ success rate: 43 percent

Allen has all the makings of being a huge bust in the NFL. His overall completion rate (56 percent) ranked him 88th out of 113 passers making at least 200 attempts in 2017 and his 40-percent completion rate under pressure was the eighth lowest among college quarterbacks. Football Outsider’s QBASE model — which uses stats such as completion percentage, adjusted yards per attempt and team passing efficiency, with an adjustment for teammates and opponents, to project the careers of the NFL’s top quarterback prospects — handed Allen a QBASE score of negative-83. Since 1997, there have been 27 quarterbacks chosen in the top 100 with QBASE ratings below zero and the best performers of this group in the NFL was either Josh McCown or Brian Griese. This is in line with Allen’s 43 percent S&P+ success rate referenced earlier, which puts Blaine Gabbert and Jake Locker as his comparable players.

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