Rankings changing in the offseason? How?

As a reader, it undoubtedly gets puzzling when you read mocks and rankings only to see the players and picks moved around on a regular basis. After the completion of the college football season, how could such things happen?

Well, for me at least, it’s a multifaceted explanation.
Most draftniks put a lot of stock into how a player performs during practice at the Senior Bowl and Shrine Game practices. While it does hold some importance, I base most of my rankings on how a player has played.
Now, having a full-time job often inhibits me from watching a ton of games during the season. I live in the heart of Big Ten country, so my typical Saturday during conference play consists of watching Big Ten, Big East and Mid-American Conference football during the day. In the evenings, I’ll catch the game of the day and Pac-10 or Mountain West football at night. My DVR is always recording a few games on Saturday and I try to catch most of the games during the week.
That, I think, gives me a good base opinion, but it’s not good enough. So, after the season, I go back and watch a lot of the games that are on the DVR or that I’ve received on DVD. For instance, last night I watched the Boise State/San Jose State game to observe defensive tackle Jarron Gilbert. That’s the third, and most impressive, game I’ve seen of Gilbert from 2008. Based on that, and some other news that has come out, he’ll be higher in the next set of rankings.
Another way a player moves up the rankings is through word of mouth. Since I don’t have access to coaches tape, can only go to so many games and see so many televised, it’s important to trust some other voices. For me, those voices include Todd McShay, Scott Wright of Draft Countdown and my old pals at New Era Scouting. If the consensus from those guys (and a few others) is radically different from my opinion, I like to go back and reevaluate my stance on a player.
Contacting beat writers who cover the colleges is a key tool as well. That’s also where a lot of the character analysis is found.
Most draft sites probably won’t share this sort of stuff because they want the readers to think they know everything and have unlimited time and access. That is certainly not the case, unless you’re a “name” draft person. And there are very few of those.
So, the idea here, is to be knowledgeable, but also transparent. So if you get curious about adjustments and such this time of year, hopefully this explains it.