(A series looking at the top players at various positions leading up to the 2014 NFL Draft, set for May 8-10.)

Nine. That's how many defensive linemen entered the NFL as first-round picks last April, and that served as further proof of what the late George Young once termed the Planet Theory.

Young, who died in 2001, was a five-time NFL Executive of the Year who built championship teams for the Baltimore Colts and the New York Giants. According to Young, the Planet Theory stated that there are only a very few human beings on the planet who are big enough and athletic enough to excel along the line of scrimmage in the National Football League. Therefore, you pick those guys early.

That's why there were 18 offensive and defensive linemen drafted in the first round of the 2013 draft, and that's why nobody should be surprised if something similar happens on May 8.

The top prospects along the offensive line were detailed in a previous installment of this series. Jadeveon Clowney, Aaron Donald, Stephon Tuitt, Louis Nix, Kony Ealy, Ra'Shede Hageman, and Timmy Jernigan are among the best of the defensive line.

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JADEVEON CLOWNEY**
As a senior in high school in 2010, Clowney, 6-foot-6, 266-pounds, posted 29.5 sacks, forced 11 fumbles and scored five defensive touchdowns. He started one game as a freshman at South Carolina, but he played enough in situations to finish with 12 tackles for loss and eight sacks. In 2012, Clowney finished sixth in the Heisman Trophy balloting after posting 23.5 tackles for loss and 13 sacks. In 11 games in 2013 – he missed two with injuries – he had 11.5 tackles for loss and three sacks. Over three college seasons, Clowney had 47 tackles for loss, 24 sacks, and nine forced fumbles in 36 games. Clowney has all the tools to become a dynamic defensive player in the NFL, but is he going to do the work to continue to improve in a league where raw ability will take you only so far? If Clowney learns what it takes to be a professional, he can become great.

AARON DONALD
Donald, 6-1, 285, enters the draft as the winner of every award available to a college player who doesn't handle the football. The Outland Trophy, the Nagurski Award, the Lombardi Award, and the Bednarik Award – Donald won them all for his 2013 season. In his three seasons at Pitt, Donald (pictured above) posted 27.5 sacks and 63 tackles for loss. He was a team captain and the first Pitt defensive player to be a unanimous All-America since Hugh Green in 1980. For purposes of comparison, think of Donald as Warren Sapp without the big mouth. At the Combine, he posted the fastest 40-time among the defensive tackles (4.68) and did 35 repetitions of 225 on the bench press. Hard worker, team captain, solid individual, and he dominated everyone he faced at the Senior Bowl.

STEPHON TUITT
His name is pronounced "stuh-FON TOO-it." Tuitt, 6-5, 304, became a full-time starting defensive end for Notre Dame in 2012, and in his final two seasons there he posted 19.5 sacks and 22 tackles for loss. A medical scan at the Combine revealed a fracture in his left foot, and Tuitt had surgery to fix that on March 1. Unlike the quick-twitch athletes whose forte is rushing the passer, Tuitt is more of a traditional defensive lineman in that he is willing to do the work necessary to stop the run. He's big, with long arms, and good strength, but Tuitt has work to do on technique and hand usage. He also didn't dominate on a consistent basis against the kind of competition he will see in the NFL.

LOUIS NIX
Nix, 6-2, 331, was a teammate of Tuitt's, and he was the starting nose tackle from 2011-13. In the first two of those seasons, Nix posted 2.5 sacks and 12 tackles for loss, but in 2013 he missed five of the final six games because of November surgery to repair a torn meniscus in his left knee. Nix has the size and bulk to command double-teams in the middle of the line of scrimmage, but he doesn't yet have the balance and ability to stay on his feet that made Casey Hampton a great nose tackle. Nix already graduated from Notre Dame and could have returned for another college season, but he entered the draft to help provide for his 13 siblings.

KONY EALY
His name is pronounced "COE-nee EE-lee." Ealy, 6-4, 273, made 25 starts over three seasons, and during his career at Missouri he posted 14 sacks and 27.5 tackles for loss. He was a first-team All-SEC defensive end in 2013. His combination of height and long arms, to go along with the athleticism that allowed him to do the three-cone drill in 6.83 seconds at the Combine, indicate he can become a successful edge rusher in the NFL. But Ealy is going to have to add strength, and he will need to learn how to play all aspects of the position. Ealy's arrow is pointing up.

RA'SHEDE HAGEMAN
Name is pronounced "ruh-SHEED HAYG-men." Hageman, 6-6, 310, arrived at Minnesota as a tight end, but after taking a redshirt in 2009 he was moved to the defensive line. In 2010 he missed four games because of academic issues, and he didn't become a full-time starter until 2012. Over his final two seasons, Hageman posted 73 tackles, 20.5 tackles for loss, and eight sacks. He also batted eight passes and blocked two kicks during a 2013 season that had him voted team MVP. Hageman also is an athletic marvel in that he posted a 35.5-inch vertical jump at the Combine while also doing 32 repetitions on the bench press. Despite the fact he will be a 24-year-old rookie, Hageman is considered to be very raw.

TIMMY JERNIGAN
Jernigan, 6-2, 299, led all Florida State interior linemen with 30 tackles, six tackles for loss, and 2.5 sacks as a freshman in 2011, but his development was slowed by injuries that caused him to miss spring practice in 2012 (sprained MCL) and in 2013 (ankle). During the team's run to the national championship in 2013, he led the team in tackles for loss as the starting nose tackle. Jernigan is strong and can clog running lanes because he knows how to play with leverage. He still has some learning to do, but he will be a 21-year-old rookie. His one special quality right now is his strength.

THE 2013 NFL DRAFT, DL STATISTICS
Number drafted: DEs: 25; DTs: 16
Picks by round: DEs: 5 in the first; 2 in the second; 2 in the third; 3 in the fourth; 5 in the fifth; 2 in the sixth; 6 in the seventh; DTs: 4 in the first; 2 in the second; 3 in the third; 1 in the fourth; 3 in the fifth; 2 in the sixth; 1 in the seventh
Highest pick: DEs: Dion Jordan, Round 1, third overall, by the Miami Dolphins; DTs: Sheldon Richardson, Round 1, 13th overall, by the New York Jets
Biggest impact: Ziggy Ansah led all rookies with eight sacks, but he would finish with 32 tackles in 14 games with 12 starts as a DE for the Lions. Richardson played in 16 games, with 15 starts, for the Jets, and he finished with 78 tackles, 3.5 sacks, and one forced fumble. Richardson had the better overall rookie year.