Only 224 get drafted (not including a handful of compensatory picks), making this all the more critical for each prospect in the process.
It's a lot to take in and of course most Bears fans only have so many hours in the day, so I've put together this handy-dandy guide to the Combine, complete with schedules and players worth keeping an eye on..
First of all, if you don't have NFL Network, you can catch up on all the video of the main drills at NFL.com's Combine page. They'll have interviews with the prospects as well as discussion from their draft experts along with most of the drills.
Of course, you can also follow anyone there on Twitter for live takes as well as press conference news.
Group 1, 2 and 3 Schedules
Group 1 is comprised of the the kickers, special teams players and the first half of the offensive line prospects, Group 2 is the rest of the offensive linemen, while Group 3 contains all the tight ends.
For Chicago Bears fans, the tight ends and offensive linemen will both be the focus, though you might also be on the lookout for some kick and punt returners since we aren't sure what will become of Devin Hester.
These groups arrive Wednesday and do some medical tests, though the bulk of the medical stuff will be dealt with on Thursday. On that day, we'll hear about the measurements as well—official height, weight, arm length, hand measurement—and any questions about lingering injury issues will be checked out (for example, Matt Barkley's separated shoulder).
Friday brings psychological testing, the bench press and the workouts for kickers and special teams players.
Both specialized tight end drills and offensive line drills will be worth watching. For the Bears, you'll want to see tight ends with good hands—the team (and fans) will be looking for athletic receivers, not blockers.
It might be hard for the Bears to get a hold of one of the top offensive line prospects, but they'll at least be looking at depth, so both guards and tackles will be of interest here.
Group 4, 5 and 6 Schedules
Groups 4 and 5 are comprised of both quarterbacks and wide receivers, while Group 6 is just running backs.
While these are always fun groups to watch, none of them are priority positions for the Bears. They have a lot invested in the backfield and have a solid corps of receivers in Brandon Marshall, Earl Bennett and Alshon Jeffery.
They'll grab a receiver at some point, but it's not critical. A backup quarterback might be nice, but this isn't a great draft for the position period, so I wouldn't be shocked if they did nothing at the position.
Arriving on Thursday, these groups will do the same schedule as the previous groups, just one day later. So their full medical is Friday, the bench press and testing is on Saturday and their on-field workouts are on Sunday.
If you're watching these players, both the position drills and the basic Combine drills are important.
Of course we want to see good hands from the receivers and burst from the running backs, but there is plenty to look at otherwise.
The broad jump helps test an athlete's explosiveness off the line, as does the vertical jump. The 3 Cone Drill shows you how an athlete can change direction while running, something that will help you see how crisp of a route a receiver might run or whether a back is capable of cutting quickly to make a defender miss.
For an excellent run down of all the main drills, check out Mike Mayock's explanations at NFL.com.
This will be fun to watch—the "skill players" always are—but in terms of scouting for the Bears, fans will have more important things to watch on other days.
Group 7, 8 and 9 Schedule
The Bears have a great defense but they won't rest on their laurels, so there is a lot to watch here. Groups 7 and 8 are both defensive linemen, while Group 9 contains all the linebackers.
With Brian Urlacher uncertain to return and guys like Lance Briggs and Julius Peppers getting towards the end of their careers, Chicago will want to be on the lookout for young impact players.
There is plenty of talent among both the defensive line groups and the linebackers and fans will want to keep a close eye for someone to jump out at them.
This group arrives on Friday, then does its full medical Saturday, its testing and bench press on Sunday and its drills on Monday.
Of course, you'll want to note what it does on the bench press Sunday, but the drills will again be the key here for Combine watchers.
You'll want to watch the broad and vertical jumps closely for your edge pass-rushers, and a good 40-time won't go awry. Of course like the receivers and backs, the linebackers and linemen have their own drills.
The individual positional drills will consist of things like a coach having players follow a ball in his hand and reacting to sudden changes in direction and players showing off their hand motion and strength in batting their way through tackling dummies.
A good set of positional drills will solidify a prospect's ranking or send scouts (and analysts) running back to their game film to double check a guy.
Group 10 and 11 Schedule
Both of these groups are defensive backs, usually split into corner and safety groups. They have the same schedule as everyone else, just pushed another day back. They arrive Saturday and do their medical exams on Sunday, their regular testing and the bench press on Monday and drill on Tuesday (the final day of the Combine).
The Bears have one of the best cornerback tandems in the league so this won't be a priority, much like most of the offensive "skill positions".
That said, they will likely look for someone to provide depth at both safety and corner.
Vertical jump is a big drill here, as well as the more specialized workouts. We'll see some hands drills as well as take a look at them backpedaling (though let's be honest, that's much more important when watching it on game film).
All throughout the week, these players will be meeting with teams so team staffs can get the measure of a player one on one. They'll chat about anything from how they'd react to a situation on the field to how they would deal with something off of it, to even things like what they listen to, read, watch on television and more.
Nothing is off topic and their reaction to a question can be as important as the answer they give.
These interviews, while done away from prying eyes, are more important than almost any drill for many players and could boost a players' stock or remove them from a team's board.
You'll hear more about the interviews the day after players leave and all of next week and it's worth listening to how players did, especially ones who have question marks.
Players to Watch
We'll start with the offensive line, and try to be realistic—because unless they want to sell the farm, Luke Joeckel and Eric Fisher will be long gone.
Oklahoma's Lance Johnson might not be gone though, and D.J. Fluker from Alabama might be there as well, though you could argue he is a stronger right tackle than left.
Dallas Thomas (Tennessee) and Kyle Long (Oregon)—and yes, son of Howie Long—are worth watching as well and could sneak into the first round.
We might also see some guards go, such as Chance Warmack (Alabama) and Jonathan Cooper (North Carolina) but there won't be a run.
Aside from offensive line players, tight ends like Stanford's Zach Ertz and Notre Dame's Tyler Eifert are guys you should keep an eye on.
Ertz has good size and speed and is a mismatch for linebackers as well, while Eifert is a big body who will fight off a crowd and haul a difficult ball in with no problem.
Both would be a huge help for Jay Cutler.
Middle linebackers are a position the Bears will have to draft for, and early at that. We have gone over this before, but keep Kevin Minter, Manti Te'o and Arthur Brown (among others) in mind from that piece.
Alec Ogletree was a guy who I have on the outside spot, but many have him as an inside linebacker prospect and given his recent DUI, he might slide to where the Bears can grab him.
Keep your ear to the ground and see how the buzz sounds on his interviews—that will give the Bears a chance at him or make them avoid him.
Even if I think he's better outside, the Bears will look at him if he's there so you should too.
There isn't exactly a ton of inside linebackers, so if the Bears want one, they have to go early—that means they'd better be sure.
So the top of the draft class for inside linebackers will be critical to watch.
If it isn't on tape, it isn't on the field. A player can crush the Combine and both teams and analysts can get caught up in that.
If you see someone break out over the next week, what it should do is make you go back and watch some games featuring the players. I like to look at his best and worst games, so you can see what works and what doesn't. That can be tougher with defensive players (who can only react to what the offense does many times) and offensive linemen (because you never know if that sack was really his fault, if the play call was bad or if someone else screwed up).
You have to look back at the tape. If it's not there, you have to balance whether the player might really have upside or if they just look good in shorts.
Ultimately if they can't do it on tape, they probably won't do it on Sundays.
Take another look, sure. But don't get too high or too low after the Combine.
After all, it's just one step in the process.