It is true that the passing numbers in the league are now higher. Nevertheless, many things have evolved. Defenses should have had more years to evolve and become more adept at reading offenses. Defenders are probably much more athletic. There should also be mitigating factors that have made it harder to pass, too. Maybe it is a little easier to pass, but I think people are taking too much liberty if they believe that rule changes are the only reason that passing numbers are higher now.
One thing that I haven't heard many say is that quarterbacks are just flat out better, now. They have evolved. Offenses have evolved. This can be compared to the NBA: in the old days, people shot the ball underhanded using "granny shots." Then, they learned that the jump shot had a better chance of getting over defenders and scoring. I think that offenses and defenses evolve over the course of years, and right now, the offenses have the advantage over defenses. But, over time, the defenses may develope strategies that neutralize the advantages of today's offenses. Personally, Ithink that quarterbacks (and their receivers) are just, on average, better today than they were years ago--although there have been some great ones in the past. Quarterbacks share information and learn ways to read defenses, thus the entire positionevolves to become better. I imagine much of Eli's success has to do with the small tricks and details that he learned from discussing things with Peyton and his father, Archie. I think the entire group of quarterbacks in the NFL progresses this way.
I alsothink today's offenses are just better, on average. Though rule changes have affected it somewhat, I think the evolution of the game explains more of it. Rule changes probably explain some of it, but I honestly believe that if you put some of today's quarterbacks back into the old world of NFL, they would torch the defenses--even if the old rules were in effect. Nevertheless, in time, defenses will probably develop strategies to become more effective. It probably works in sort of a thesis-antithesis way. What do you folks think about this?