Each day leading up to the 2018 NFL draft, I’ll break down one of my top 50 prospects. In some cases, we had to make tough omissions because of injuries, poor pre-draft workouts or incomplete information. For more complete scouting reports on all the prospects, check out the Pro Football Weekly 2018 Draft Guide, which is available for order now.

16. Iowa CB Joshua Jackson

6-foot-1, 192 pounds

Key stats: Entered 2017 with zero interceptions but led the nation with eight picks last season in his first full year of starting.

The skinny: A prep receiver out of Lake Dallas High School in Texas, Jackson — a two-star prospect with little fanfare — arrived in Iowa City without much experience as a defensive back. But during his redshirt season of 2014, the coaches moved him from wideout to corner and it would take a while for him to make his impact felt.

In 2015, Jackson played in all 14 games as a reserve on defense (eight tackles, two pass breakups) and contributing on special teams. As a sophomore, Jackson played in 12 games (starting only Iowa’s Outback Bowl loss to Florida) and finished the 2016 season with 10 tackles (one for loss) and four pass breakups.

His first career interception came in the 2017 opener against Wyoming — and possible No. 1 overall pick Josh Allen — and he’d add seven more through the course of a brilliant final season. Jackson started all 13 games at corner, adding 18 pass breakups and one forced fumble, winning the Jack Tatum Award and being named a Thorpe Award Finalist. He also was named consensus All-American and First Team All-Big Ten. Jackson also contributed on special teams, with a blocked field goal against North Texas and a 7.2-yard average on five punt returns during the season.

Jackson declared for the 2018 NFL draft. He participated in all the tests (except the 60-yard shuttle) at the NFL scouting combine and bettered most of his numbers at Iowa’s pro day.

Upside: Nice height, weight and athletic build. Athletic testing numbers were mostly very good, including strong vertical jump (38 inches at combine, 40 at pro day), short shuttle (4.03 seconds at combine, 3.95 at pro day) and bench press (18 reps). Other numbers, such as broad jump (123 inches) and 3-cone drill (6.86 second), were well within good range for his size, and Jackson improved 40 time from combine (4.56 seconds) to pro day (4.52).

Effective working in press and off coverage. Also showed great zone instincts and looked like a seasoned pro when he finally got his chance. Played outside and in the slot and on both sides of the field. Finished strong — Jackson was probably the nation's best cover corner down the stretch last season. Turn on the Ohio State and Wisconsin games, and Jackson looked like Marcus Peters out there.

Flashed outstanding playmaking ability in final season — stunning 27 passes defended, eight INTs. Catches the ball like you’d expect a former receiver to do. Tested often last season and held up to the challenge far more often than not. By one team’s count, Jackson only allowed 36 receptions on 86 passes thrown at him last season. Rarely allowed downfield catches. Plays the ball very well in the air (see third quarter vs. Wyoming) — plays the ball, not his man. Took two INTs to the house vs. Wisconsin.

Fluid hips to turn and run. Has leaping ability and good recovery ability. Big hands to press and reroute receivers at the line. Plays a physical brand of football and can work against size well. Closes extremely quickly on the ball. Sees and reacts. Check out the fine zone instincts (or film-study play?) here by Jackson against Ohio State as he passes off his initial man, smells the underneath crosser and closes on it beautifully for a game-changing INT in a close game right before halftime:

Arrow pointed way up — only started playing corner in 2015 and has shown immense improvement in short time. There might have been no bigger difference among defensive backs in this class between his limited 2016 tape and how he performed in 2017. Has blitz potential. Willing run supporter who will come up and lend a hand. Quick hands and will look to pop ball loose from unsuspecting runners (see Wisconsin game).

Iowa program has had success developing DB talent in recent years, including Micah Hyde and Desmond King.

Downside: Might always be challenged by speed. Even with his 40 improvement (and game tape that shows he plays fast), his tested speed barely meets minimum for the position, even at his size. And it’s good size, not elite by any means — arm length (31 1/8 inches) actually considered below-average.

Positional technique remains a bit crude — looked clunky in combine position drills when asked to flip hips and transition. Gets stuck in “half-turn” position in zone coverage, even on in-breaking routes. Stays flat-footed in zone and can get caught napping once in a while. Gives too much cushion in off coverage isn't always in position to close on comebacks, slants and quick outs. Teams looked to nickel and dime him and often were able to do so. Will get a little handsy too far downfield.

Not as effective in the slot against quick receivers. Here, Jackson has what should be a good matchup against Iowa State’s king-sized receiver, Hakeem Butler, who was making only his third career start. It’s 4th-and-1, Iowa is in a cover-0 blitz (all-out pressure, no deep safety help) and Jackson bites way too hard on the initial move inside, falls down and is roasted on the “sluggo” route for the touchdown:

Tackling needs work. Ankle diver at times who will whiff in space. Allowed a few runners to get outside him. Needs to get off blocks better — receivers had success cut blocking him and he didn’t always fight through picks well enough. Didn’t face a gauntlet of top-tier wide receivers last season. Limited punt-return experience (five returns in 2017) and no kick-return experience.

Best-suited destination: Jackson has terrific instincts and would thrive on a defense that emphasizes zone coverage. He also could contribute as a nickel defender, and perhaps be a solid second punt returner, making him a Day 1 contributor on almost any team. Among the teams that could be good fits for Jackson include the Pittsburgh Steelers, Carolina Panthers, Green Bay Packers, Seattle Seahawks, Arizona Cardinals, Cincinnati Bengals, Cleveland Browns, Miami Dolphins, Oakland Raiders, Chicago Bears, Tampa Bay Buccaneers, Indianapolis Colts, Dallas Cowboys, Atlanta Falcons, San Francisco 49ers, Buffalo Bills and Washington.

Quotable: “He was not good [during positional work at the combine]. .. He looked stiff. If you’re taking him with a first-round pick, that's risky to me.” — College DB coach

Player comp: Stephon Gilmore

Expected draft range: Top 25

Greg Gabriel scouting report (subscribers only)

Previous profiles

50. Oregon RB Royce Freeman
49. South Dakota State TE Dallas Goedert
48. LSU DE-LB Arden Key
47. Ohio State C Billy Price
46. Alabama S Ronnie Harrison
45. Oklahoma State QB Mason Rudolph
44. Texas A&M S Armani Watts
43. South Carolina TE Hayden Hurst
42. UCF CB Mike Hughes
41. USC RB Ronald Jones II
40. Maryland WR D.J. Moore
39. UTEP OG Will Hernandez
38. Stanford DT Harrison Phillips
37. Ohio State DE Sam Hubbard
36. Stanford S Justin Reid
35. Oregon OT Tyrell Crosby
34. SMU WR Courtland Sutton
33. Penn State TE Mike Gesicki
32. Colorado CB Isaiah Oliver
31. Georgia OL Isaiah Wynn
30. Texas A and M WR Christian Kirk
29. Alabama LB Rashaan Evans
28. Alabama WR Calvin Ridley
27. Michigan DT Maurice Hurst
26. Texas OT Connor Williams
25. Georgia RB Sony Michel
24. LSU RB Derrius Guice
23. Boise State LB Leighton Vander Esch
22. Florida DT Taven Bryan
21. Wyoming QB Josh Allen
20. Notre Dame OT Mike McGlinchey
19. Iowa C-OG James Daniels
18. Alabama DL Da’Ron Payne
17. Louisville QB Lamar Jackson