One thing that must be considered is the system each QB plays within. Manning and Big Ben throw a lot of picks, and so did Marino and Elway, because they QB in a vertical stretch system, where their throws are all medium and deep. It's high risk/high reward. You're going to get some picks in exchange for those long backbreaking bombs. Rodgers and Brees are in more QB-friendly offenses, so they are going to be less prone to picks, and their completion percentages will tend to be higher due to all the short and medium passes that are a staple of their offenses. I'm not going to diminish Rodgers and Brees' accomplishments, because they've been prolific, but I'm also not going to penalize Manning and Big Ben for being in offenses that are not so stat friendly.