'09 NFL Draft: Top 10 DB prospects Story Highlights Ability to play defend the run separates top two cornerbacks from pack Vanderbilt's D.J. Moore can do it all and has a knack for making plays Poor senior season pushed Missouri's William Moore down draft boards Vanderbilt cornerback D.J. Moore's abilities as a return man will help his draft stock. Icon SMI Bucky Brooks's Mailbag Have questions or feedback? E-mail Bucky Brooks. With the NFL combine set to begin this week in Indianapolis, SI.com's Bucky Brooks, a former scout, is ranking the top 2009 draft prospects by position group. The lists were compiled through a series of conversations with scouts and game-tape evaluations. The schedule will be as follows: Defensive backs 1. Vontae Davis, Illinois, CB: A polished corner with outstanding cover skills and instincts, Davis is a smooth, fluid athlete with exceptional movement skills and excels in man or zone coverage. He maintains great leverage on receivers down the field, and flashes an explosive burst out of his breaks. His ability to close on receivers is impressive, and he has a knack for making plays on the ball. Not content to be a "cover corner", Davis also shows up against the run. He is a sure tackler who also delivers big hits when he gets a chance. Overall, Davis is a talented cornerback who has the ability to make an instant impact as a first-year starter. 2. Malcolm Jenkins, Ohio State, CB: An aggressive corner with outstanding ball skills and awareness, Jenkins excels in a zone-based scheme that allows him to sit off and read routes. Though there are concerns about his top end speed, Jenkins plays with outstanding discipline in coverage and rarely is out of position down the field. Jenkins drives short and intermediate routes well and shows an explosive burst out of his breaks. As a run defender, Jenkins is an aggressive hitter and tackler on the edge. He works quickly off blocks, and aggressively steps up to fill gaps. In fact, his skills as a run defender are so good that some scouts are of the opinion that he would be an outstanding free safety prospect. Regardless, Jenkins is a gifted corner who would be an ideal fit in a cover two-type scheme. 3. D.J. Moore, Vanderbilt, CB: A "do-it-all" playmaker with exceptional cover skills, Moore is an instinctive corner who shows outstanding footwork and instincts in coverage. He reads routes well and flashes a tremendous closing burst to the ball. He attacks the ball like a receiver, and his 12 interceptions reflect his prowess as a ball hawk. Moore's outstanding athleticism also shined when he filled in as a receiver/returner for the Commodores. As a skilled two-way player, Moore shows big play ability with the ball in his hands, and his potential to produce game-changing plays makes him an intriguing possibility as a corner/return specialist. While Moore lacks the household name recognition of some of the others on the board, he has skills and potential to be an all-star as a pro. 4. Alphonso Smith, Wake Forest, CB: A ball hawking cornerback with exceptional ball skills and awareness, Smith is smooth and fluid in his movements, and shows outstanding closing quickness out of his breaks. The sensational cover man has an unbelievable knack for getting his hands on the ball, and his 21 career interceptions is an astonishing achievement for any corner. Though Smith's size (5-foot-9, 190 pounds) concerns some scouts, he offsets his height advantage with his outstanding leaping ability and rarely appears to be overmatched on the perimeter. With cover skills that rival any player on the board, Smith could be the sleeper that emerges as the best corner in this year's draft. 5. Darius Butler, Connecticut, CB: An athletic corner with outstanding size, speed and movement skills, Butler is a solid zone corner with good instincts and awareness. He aggressively jumps routes and flashes an explosive burst out of his break. Though he failed to record an interception this season, Butler shows adequate ball skills and awareness while roaming in zone coverage. As a man-to-man defender, Butler has athleticism to shadow receivers from "press" or off coverage. He consistently stays in the opposition's hip pocket and finishes well at the end of routes. Butler impressed scouts with his solid play during the Senior Bowl and will make another move up draft boards with an impressive showing at the Combine. 6. Patrick Chung, Oregon, S: A versatile, hard-hitting safety with outstanding skills, Chung moves well in space and shows impressive skills as a pass defender. He has the range to get over the top on deep throws, but is also instinctive enough to make plays on intermediate throws within his area. Chung doesn't consistently make plays on the ball, but his penchant for delivering big hits on receivers serves him well as the Ducks' enforcer in the middle of the field. Additionally, Chung is a standout run defender who aggressively meets ball carriers in the hole. He strikes runners squarely and rarely misses tackles in space. Chung is a highly coveted prospect who is capable of stepping in at either safety spot during his first year. 7. Louis Delmas, Western Michigan, S: An aggressive safety with outstanding instincts and awareness, Delmas roams the middle of the field with confidence and is a violent force against the run. Though he has a well earned reputation for delivering big hits on runners, Delmas is an outstanding tackler who rarely misses in space. As a pass defender, Delmas is a rangy player with the instincts and athleticism to get over the top on deep throws. His outstanding speed erases his early missteps in coverage and allows him to make an impact as a deep middle player. With an exceptional combination of athleticism, speed and movement skills, Delmas has the potential to be a dynamic free safety as a pro. 8. Sean Smith, Utah, CB: Smith is a raw, unpolished cornerback prospect with rare size (6-3, 210 pounds) and intriguing physical tools. He relies on his exceptional athleticism to overcome his shoddy technique in coverage. He routinely makes plays on the ball after appearing out of position early in routes. As a former receiver, Smith possesses good ball skills and his sure hands resulted in nine interceptions in his two seasons as a starter. However, some scouts view Smith as a "boom or bust" prospect who will struggle as a pro due to his lack of experience and skill refinement. Nevertheless, expect a team to make a play for Smith early due to enticing size and potential. 9. William Moore, Missouri, S: Moore is a once-highly regarded safety prospect who suffered through a disappointing senior season due to an assortment of injuries. As a classic strong safety with exceptional size and instincts, Moore is at his best when playing near the line of scrimmage. He quickly diagnoses running plays, and is an aggressive hitter in the hole. His ability to stop runners in their tracks is impressive and adds to his intimidating presence. As a pass defender, Moore isn't fluid in all of his movements, but has the savvy and instincts to get into proper position when the ball is thrown. He has 11 career interceptions, including eight as a junior, and shows an uncanny knack for producing game-changing turnovers in the back end. Though scouts are downgrading Moore for his sub-par performance during his senior season, he was simply too good as an underclassman to be ignored as a potential impact pro prospect. 10. Cary Harris, USC, CB: A tough, hard-nosed corner with solid all-around skills, Harris is a solid technician who plays with great discipline and focus in coverage. He is sound in all aspects and is rarely out of position when the ball arrives. Though he lacks the ball skills to come up with game-changing turnovers, his consistency in coverage and competitiveness offset his lack of playmaking ability. As a run defender, Harris is an aggressive tackler who doesn't mind mixing it up on the edge. He quickly works off blocks and repeatedly shows up in the running support. Harris' toughness stands out on tape, and scouts view him as a top notch competitor on the perimeter. While Harris is not in the class of the first tier of corners, he is a sleeper pick who could develop into a solid nickel corner as a pro.