Newton's backers would defend his Pro Bowl nomination last year by quoting that Newton set a single-season record for rushing touchdowns by a quarterback (14) and became the first player to pass for 4,000 yards and rush for 500 yards in a season.
Those are impressive marks on their face but they are quantity-based and occurred after a lockout-truncated offseason. As I mentioned in my fantasy football draft guide, the lockout hurt defenses' ability to practice blitzes, which was a primary factor in why passing offenses were so explosive early on.
This impacted Newton as much as anyone, as he threw for 374 or more yards in three of his first four games. Once defenses started to get up to speed, however, Newton wasn't close to as effective a passer, throwing for 208 or fewer yards in five of his last six games.
These defensive adjustments are a main reason why Newton came up short in the areas of vertical yards per attempt (10.5, tied for 21st) and stretch vertical yards per attempt (12.6, tied for 17th). (Note: vertical passes are aerials thrown 11 or more yards downfield; stretch vertical passes are thrown 20 or more yards)
Newton also came up well short in ESPN's Total QBR metric (56.6, ranked 16th) and he posted a 4.2 percent bad decision rate (BDR) that was the fifth-highest mark in that category last season. (Note: BDR measures how often a quarterback makes a mental error that leads either to a turnover or a near-turnover such as a dropped interception)
There is little doubt Newton's incredible drive will, when combined with his talent, make him a Pro Bowl-caliber quarterback in the future, but he isn't quite there yet.
It's an insider article so I can't link it.