For any quarterback who has and uses the ability to make plays running the football, the question is always the same: Will he take too much of a pounding and get bitten by the dreaded injury bug?
Mobile quarterbacks like Michael Vick have long been prone to injury, but Carolina Panthers quarterback Cam Newton will be the one to break the mold, mostly because he's a completely different type of player.
The main difference between Newton and traditional quarterback running threats like Vick is size.
Whereas Vick stands at barely six feet tall and weights about 215 pounds, Newton is a mammoth of a man, checking in at 6'5" and 248 pounds of solid muscle.
His elite speed is what allows Vick to be so effective when taking off to run, but when his body is taking the hit, that speed no longer matters and he's just being delivered a hit from a much bigger man.
When confronted with would-be tacklers, Vick really only has three options: try to run past them, slide or take a hit.
The Eagles quarterback doesn't help himself by neglecting to use the safety slide as often as he should, and therefore subjects himself to big hits from opposing defenders if he can't run by them.
Newton's running style when he takes off with the football differs from Vick in this way.
While Vick is always using his speed to look for lanes to run by defenders in the open field, Newton's size gives him another option in addition to the ones at Vick's disposal in this situation: Newton can use his big frame to deliver a blow to the defender and gain a few extra yards.
In fact, he often looks to do exactly that.
Delivering the blow instead of always taking it will save Newton from some of the big hits Vick has taken in his career.
This weapon is what has made him such a devastating runner near the goal line already in his career. He showcased this type of power running by getting two scores on the ground against the Chicago Bears on Sunday.
Vick was also a much less advanced passer early in his career than Newton has proven to be.
Quite simply, Cam has set a historic pace with the first four starts of his career.
At one point he held the all-time record for passing yards in the first two games of a season—not for a rookie, for everybody—only to see the great Tom Brady break it later the same day.
Newton has completed 97 of his 163 passes for 1,386 yards, five touchdowns and five interceptions in his first four games.
Newton's completion percentage through his first four starts is 59.5.
Vick's season completion percentage has only exceeded that number once in his career, and that was last season.
Keep in mind that through two games Newton's completion percentage was 62.6, and then he completed just 18-of-34 passes against the Jaguars in Week 3's monsoon.
He then came back and completed 27-of-46 passes for 374 yards against the vaunted Chicago Bears defense in Week 4.
Even in college, Newton was a more accurate and productive passer than Vick was.
In Newton's one year at Auburn, he completed 185 passes for 2,854 yards and 10.2 yards per attempt. He threw for 30 touchdowns and seven interceptions.
It took Vick nearly two seasons to compile similar numbers.
In his two years at Virginia Tech, Vick completed 192 passes for 3,299 yards and 9.6 yards per attempt. He threw for 21 touchdowns and 11 interceptions.
Newton's ability to make plays from the pocket has already changed the complexion of the Panthers offense.
Cam has been called on to throw the football much more often already in his career than Vick ever was when he was with the Falcons.
So far, it seems like he only takes off to run as a last resort, as he has both shown a willingness to stand in the pocket and deliver the ball while taking a hit, and to keep his head looking down the field until he passes the line of scrimmage.
Newton's abilities as a passer will require him to make plays with his legs less often than Vick.
Quarterbacks who stay in the pocket are afforded more protection from big hits because of the safety rules in place to protect them.
Once the quarterback leaves the pocket, he becomes a runner and the rules are much more relaxed, leading to more vicious hits.
Like Newton, Roethlisberger is 6'5" and over 240 pounds (Ben checks in at 241).
Newton and Roethlisberger's career completion percentages in college were quite close as well.
Ben completed 65.5 percent of his collegiate passes to Newton's 65.4 (if you include his two years at Florida).
Although Roethlisberger wasn't called upon to throw nearly as often as Newton early on in his NFL career, he showed a similar willingness and ability to stand in the pocket and deliver the ball while being hit, to deliver the blow to defenders when he took off and ran with the football and to make big plays in the passing game.
Although he threw just 295 passes as a rookie, Ben averaged 8.89 yards per attempt.
Newton is at 8.5 yards per attempt through four games.
By way of comparison, Vick's yards per attempt in his first year as a starter was 6.97.
Newton's yards per carry average of 4.0 is also much closer to Roethlisberger's 3.3 career average than Vick's 7.1.
Roethlisberger's size and style of play have led to him missing just seven games due to injury in his seven-year career, as opposed to Vick's 18 missed games in eight seasons.
Because Newton will not be subjected to the same type of hits as Vick, and because his running style is different from that of Vick's, I just don't see him having the same type of injury problems in his career.