The Physics Behind Curveballs

With the MLB All-Star Game happening, you might be wondering how curveballs and other pitches actually work. Well wonder no longer because Derrick has the answer for you! It all has to do with the 216 raised red stitches altering the airflow around the ball.
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If the ball leaves the pitcher’s hands spinning counterclockwise like above, the stitches are causing air to move faster above the ball than it does below. If you remember our post about Bernoulli’s Principle, you’ll know that this creates a lower pressure zone above the ball. That lower pressure causes a form of lift referred to as the Magnus Effect, keeping the ball from dropping as much on its way to the plate, delivering a fastball to the batter.
If the pitcher instead twists their wrist in another direction, the Magnus Effect pulls the ball in the direction of lower pressure. Pitchers can use this to make balls drop to the ground quicker or veer off to the side, giving curveballs their namesake.