I don't objectively measure a potential players worth (or value). I use the subjective draft guides. And read what other people are saying about them subjectively in the media. I come out here and read what people are posting about them and where they think their value should be. I watch some you tube videos on how they play. Or watch them in a real game on TV. And then I subjectively make a decision on whether people are right based on what I have seen in the past.
That's the way everyone does it. Because football is the ultimate team sport. There are so many things that can effect how well or how poorly you do. How you are perceived. There are so many things that can effect where a player is ultimately drafted. Nobody seriously believes La'el Collins is a UFA talent. But it happened.
But ultimately its not where you are drafted anyway. Its about your potential to produce at a high level in the NFL. And that is completely subjective. Because nobody really knows for 100% sure. Look at Tom Brady. 6th round pick. Or Tony Romo. UFA.
Anybody can be a diamond in the rough. That's why it is so very important to have as many draft picks as possible. The more picks you have, the better your odds to find one of those guys.
The bottom line is consensus of opinion is the way humans do it. Objectivity is important. Or at least a form of it. But its only part of the equation of the human experience.
I have no problems with what you said except for one thing: you nor any of the people who make and read these draft publications have to make the pick. So subjectivity is all you and I have to go on.
However, the teams are the ones who have to pull the trigger. For them, this is not merely a subjective endeavor. It is an OBJECTIVE endeavor because it could prevent their teams from getting better and could cost them their jobs. So their consideration is a bit different than yours and mine.
Furthermore, let's make a distinction between round ranking and team value. Round rankings are based on a player's talent. Team value is based on more, including character, scheme and how the player will fit the team. The former is more important to fans, the latter more important to teams.
So a Carl Brantley may be graded as a first or second round, but he dropped to the 6th round because of his domestic violence charge.
I think fans make a mistake slotting players based on talent alone. Moreover, draft reviews don't consider the number of players who can and will be drafted. Every player is given a draft rating, and more ratings are assigned than draft picks. But we know every player with a rating isn't going to be drafted. Or you may have 35 players with 1st round ratings. But there aren't going to be 35 players drafted in the 1st round.
So ratings have a built in subjectivity. That's why I say the only thing that matters is where a player goes on draft day. Where he goes ultimately establishes his draft value. It doesn't matter where you or I think he should have gone. We operate from incomplete and subjective information. The teams operate with complete information and control the outcome of where a player is taken.
