Catching a football like pros is no easy task, especially when you have some of the hardest throwing quarterbacks in the world. A football of an NFL quarterback can be close to 60 mph(26m/s) , weighing roughly .4kg. This creates a momentum of roughly 10 kg times meters per second. this number may not seem large until it is coming toward you with 11 defenders making sure you don't catch that ball. In order to stop that ball you must apply just as great of a force back at the ball while squeezing hard enough to keep the ball in your hands. Doing this is always easier said than done. NFL receivers really do have a difficult job to do.