This blog post was inspired by MyloXyloto's post: "Frisbee Fysics," Check it out!
In football, throwing the ball with spin is called throwing a spiral. The better the spiral, generally the better the pass and the easier it is to catch. But why in football does spin make the ball easier to catch while in baseball spin makes the ball harder to hit? Well, in baseball, spin makes the ball curve. Different amounts of spin will make the ball curve at certain times or certain speeds, making the baseball harder to hit with bat. However, in football, the spin on the ball does not do that.
When the football is thrown it immediately has angular momentum, and if thrown without being tipped or hit somehow, the football will remain in the same orientation. This is valuable because it makes the ball land in the receiver's hands quite easily because it will generally be caught the same way every time. In addition, because the football is in the same orientation throughout its entire flight, the ball will experience the same amount of air resistance and will therefore keep a straighter path. Imagine a football flying at you in a random pattern, and it is moving side to side slightly in the air. It will be hard for you to predict how and where to catch it compared to if the football was on a straight path right to you.
In all, the importance of the spiral when throwing a football is accuracy! Tight spiral = quality pass.