DETROIT -

The NFL draft is an event surrounded by guesswork and speculation as "experts" predict which players will be drafted and how those selections will pan out. Thousands of mock drafts contradict each other with predictions that include the Detroit Lions trading into the top five to draft Sammy Watkins or selecting cornerbacks, tight ends, linebackers and wide receivers at No. 10.

While predicting the future can be an exceptionally imprecise art, looking back on selections from the past can create a clearer picture of how a team performed during a given draft.

One of the most influential drafts in recent Lions history was in 2009, when they held the No. 1 overall pick after finishing 2008 0-16. Detroit made 10 picks throughout the course of the draft, and many of those players have made significant impacts since.

Five years after these players were selected to come to Detroit, here are grades based on their performances with the franchise.

Round 1, Pick 1: Detroit selected QB Matthew Stafford out of Georgia

For years Detroit struggled to find a quarterback with the talent to take over as the face of the franchise. The Lions missed on former Oregon quarterback Joey Harrington and tried to progress with replacement-level options like Jon Kitna and Daunte Culpepper.

The Lions sorely needed to draft a franchise quarterback, and took the best available option with Stafford. The former Bulldog has had a roller-coaster career through five seasons, missing 13 games in 2010 only to return and throw for over 5,000 yards in 2011. Stafford has taken steps backward in each of the two seasons since that breakout campaign but clearly possesses the talent to be a top-tier NFL quarterback.

If Stafford could cut back on the interceptions, then he would stand as one of the top statistical quarterbacks in the NFL. In the last three seasons he has thrown for 14,655 yards and 90 touchdowns while starting all 48 games for Detroit. The 26-year-old has shed the injury label and given the Lions an above-average quarterback. Stafford is playing under the scrutiny that only a No. 1 overall pick attracts, and thus his mistakes are often magnified.

Stafford Grade: B+

Round 1, Pick 20: Detroit selected TE Brandon Pettigrew out of Oklahoma State

The first round is very early to draft a tight end, so when they are chosen on day one they are held to a high standard. For a Detroit team coming off a winless season, many of its needs were far more glaring than at the tight end position.

Pettigrew was productive during the 2010 and 2011 seasons, gaining a combined 1,499 receiving yards and scoring nine touchdowns. But in the two seasons since the Lions made their playoff run in 2011, the tight end has struggled with dropped passes and fumbles.

Overall, Pettigrew hasn't lived up to the value expected from the 20th selection, averaging 565.6 yards and 3.2 touchdowns per season.

Pettigrew Grade: C

Round 2, Pick 33: Detroit selected S Louis Delmas out of Western Michigan

Detroit went with the local kid in the second round, grabbing Delmas from Western Michigan in Kalamazoo. Delmas gave the Lions an outspoken defensive leader that they needed, but the safety has battled injuries throughout his five-year career.

He played a full 2013 season after missing 13 games from 2011-2012 and picked off a career-high three passes. Delmas has been one of the better secondary performers for the Lions since 2009, recording six interceptions and 239 tackles.

Delmas Grade: B+

Round 3, Pick 76: Detroit selected LB DeAndre Levy out of Wisconsin

Levy has been one of the few mainstays in the Detroit lineup since being selected in the third round, playing in all but seven games during his career. The linebacker specializes in pass coverage, which fits well with a Detroit defense that features a strong defensive line and thin secondary.

Levy enjoyed the best season of his career in 2013, intercepting a team-high six passes and recording 85 tackles. Detroit got great value from this third-round pick.

Levy Grade: A+

Round 3, Pick 82: Detroit selected WR Derrick Williams out of Penn State

Detroit's reputation for striking out on wide receivers reared its ugly head again in 2009 when it took a chance on Williams. The former Nittany Lion caught just nine passes in his two-year career before being waived after the 2010 season.

Williams Grade: F

Round 4, Pick 115: Detroit selected DT Sammie Hill out of Stillman

Martin Mayhew made up for the Williams pick by finding a diamond in the rough in the fourth round. Hill started 12 games on the defensive line as a rookie and played a significant role in the deep rotation from 2010-2012.

Anytime a team can find a player in the later rounds that makes an immediate impact, the pick is a success. Hill contributed to the elite depth that Detroit enjoyed at defensive line during the three-year stretch that included a playoff appearance.

Hill Grade: A

Round 6, Pick 192: Detroit selected RB Aaron Brown out of TCU

The Lions took a flier on Brown in the sixth round because of his speed and ability to catch the ball out of the backfield at TCU. The running back gained a total of 215 yards in his rookie season, which ended up being his most productive in Detroit.

Brown was let go before the 2011 season after appearing in six games in 2010.

Brown Grade: B

Round 7, Pick 228: Detroit selected OT Lydon Murtha out of Nebraska

Detroit tried to send Murtha to the practice squad after drafting him, but the Miami Dolphins signed him to their active roster in 2009.

Murtha Grade: N/A

Round 7, Pick 235: Detroit selected Zack Follett out of California

Follett spent the beginning of his rookie season on the practice squad before being promoted to the roster as a special teams player. The rookie excelled in his role, contributing on kick coverage and developing a reputation for big hits.

Follett's career ended in 2010 due to a neck injury, but Detroit got good value from this seventh-round selection in his rookie season.

Follett Grade: B+

Round 7, Pick 255: Detroit selected TE Dan Gronkowski out of Maryland

Gronkowski was only active for two games during his rookie season before being traded to the Denver Broncos before the 2010 season. The Lions likely weren't banking on much production from this final pick.

Gronkowski Grade: N/A

Detroit missed on two of the earlier selections in the draft, but many of the players became key contributors on a team that made a playoff run just three seasons after finishing 0-16. In his first draft as Lions general manager, Mayhew labelled himself as a quality drafter and put the team in a position to compete after many years of irrelevancy.

Overall Draft Grade: B+