The MVP award isn't cut and dried based on who contributed the most for the team over 16 games necessarily. If that was the case, we'd just look at the won/lost record and anoint someone on the team with the best record as the MVP. Fortunately that's not the case. Next comes body of work. Some people believe it's the best job done over 16 games. That would leave Brady out of the mix because he missed games. It would leave Rodgers out of the mix because he had a few off games. Unfortunately, too many voters believe that's the case, but it's wrong.
Yes, those are two points towards the decision, but far from being the deciding factors. One factor you can't measure, in stats, is "heart." There are guys out there that "will" their team to wins despite the lack of talent around them. These guys are by far more important in their own right, than a guy on an extremely talented team who puts up big numbers because of his support cast. They can also be more important over a shorter span of games than 16, because quite honestly, they play 16 for a reason. There's a point where redemption is possible, by the body of work during a crucial point in the season. The perfect example of that is George Blanda in 1970. He was a 2nd string QB and place kicker. But, when asked to step in as a "relief QB," he lit the league up in several games. He took the Raiders on his shoulders and lifted them to a Western Division Championship, and a run that only ended in the AFC championship game. What Blanda did wasn't a season of high level work but a level of work that was so important to his team that it lifted them to a higher level than they might possibly of never achieved if he wasn't there.
In Dallas they have Prescott and Elliott. Both contributed to the team's success. Was one more influential in making it happen, or the other? Were the pieces already in place that they could have done well without one, but not the other? You have to decide what they'd be like without either one of them as an individual. Then you do the same thing, by removing Ryan from the Falcons, Rodgers from the Packers, and Brady from the Pats. That is one of the points that must be considered.
Then there's the issue of "team leadership." A leader inspires others through their ability to set the pace that others follow. Which, of all the players we discuss, show that inspirational ability to shape, and form, the results of others?
Then there's something else you need to evaluate. The ability to perform at a substantially decent level, when your team is not capable of being highly competitive. You have to evaluate, in your mind, how well that player performed in a team effort, trying to create a win. That player's stats may not be lofty, but does he find ways, within the game, to at least give them an outside chance of winning, or does he fold it up, and wait for the next game?
But, I wonder how many real voters for the MVP award take the time to really evaluate what the true meaning of the award is, like they did in 1970, when it went to Blanda?