In the NFL, playing quarterback is all about the arm.

Which players have the needed arm strength and which don't? Today, we take on those who come up lacking as NFL lead writer Josh Zerkle and I look at which NFL quarterbacks have the weakest arm.

Arm strength isn't just throwing the ball far, although that too is important. Arm strength is a mixture of velocity and distance. Being able to throw far is great, but you also need to get it there fast. A great quarterback must have command of the ball when throwing short, medium and deep.

So which guys just can't cut it? Find out and let us know who your picks are in the comments.