Weast Coast Bias
 
Since nobody is interested in hearing my breakdown of every player, so I'm simply going to mention observations from watching individual drills by group. Day 4 is the “secondary” day at the combine featuring all of the cornerbacks and safeties. Many of the college CBs are looked at as potential NFL safeties, particularly those with less speed.

Defensive Backs
40 yard dash
Beyond the WRs, the 40 is most important to the DBs especially considering they spend their games chasing those guys all over the field. I was very surprised that only 2 guys ran sub 4.4, Demarcus van Dyke of Miami did run a top caliber 4.28 and Patrick Peterson of LSU ran a 4.34. Two others did run 4.4 dead (Chimdi Chekwa of Ohio St. and Chris Culliver of South Carolina). Typically I look for time at or below 4.5 from a CB and usually hope for a 4.65 or better from a safety.

3 Cone Drill and Shuttles
Since defensive backs are so reliant on recovery skills and reactionary quickness, these drills allow a measurable way to compare players. Buster Skrine of Tennessee-Chattanooga won the 3-cone drill with a 6.44, the 60-yard shuttle with a 10.75 and tied Idaho's Shiloh Keo for 1st with a 3.90 in the 20-yard shuttle. I was very surprised by Keo's time in both the 20-yard shuttle and 3 cone drill given his portly build and mediocre time in the 40-yard.

On-field Drills and Footwork
Their was a perceptible difference between cornerbacks and safeties throughout this drills. It was obvious that the safeties were generally uncomfortable in the backpedal, but quicker running downhill. The cornerbacks tended to stay much lower when running backwards and turning. Also the muscularity in the upper body of most safeties was noticeable, while many of the CBs had much learner frames. Nobody stood out as being especially incapable of running with players at the next level. Also I didn't see any safeties that looked like they could bulk up and transition down to the linebacker level.

Other notes
The players in this years class seem much bigger than I can every remember. It seemed like a fair number of corners were at least 6', whereas many active corners are 5'10” and below. I'm not surprised by the increase since the DBs have been trailing behind a lot of #1 receivers in the size department for the last couple of seasons. Ras-I Dowling has one of those names that I can't stand because it seems to have been given just to be unique. Patrick Peterson and Prince Amukamara, the top 2 prospects among the DBs, certainly did nothing to hurt their draft stock. I find it funny that Texas sent a pair of guys with the last name Brown that aren't related (Chykie and Curtis).