A curveball curves due to the spin of the ball as the pitcher throws is towards home plate. A whirlpool is created due to the fast spinning of the seams on the baseball. The ball turns side ways because of the difference of the pressure. From the pitcher to the catcher it is projected that a curveball can move up to 17.5 inches. One of the first curveballs thrown was 68 mph.
The baseball curves from the cause of a force that is called lift. The form of lift is a principle called Magnus Effect. A batter can tell if it is a curveball or a fastball due to the spin of the ball. A curveball spins clockwise, also the air underneath is going a opposite direction, and causing to move. The speed of a curveball depends on how many times the ball is spinning.
Professional pitchers throw these to throw off the batter. How to throw a curveball falls in the same principle of how airplanes fly. A curveball spins 1,800 revolutions per minute own the way to the plate. The ball will move 14.4 inches from the pitchers hand to the catchers glove. A curveball also falls in the Magnus Effect principle.
A curveball happens when the ball is on the way to the catcher and it is spinning a lot. A grip to throw a curveball is you put your thumb on the bottom of the ball and put your index and middle finger near the stitches. Lower pressure is caused by faster flowing air under under the ball. When you throw a curveball you are putting more stress on the air flowing under the ball. A curveball really does curve because from a pitcher, and also a batter it moves 14.4 inches from a pitcher hand to where the catcher catches it.