For a softball pitcher, it is imperative to have more than one pitch to throw to a batter. The curveball is a common alternative to a straight fastball because it has movement between when it leaves a pitcher's hand and when it reaches the batter that makes it more difficult for the batter to hit.
Technique
To throw a curveball, softball pitchers grip the ball with one or more fingers applying direct pressure to the ball's stitch as it is released. This pressure forces the ball to spin as it leaves the pitcher's hand. It is this spin, as explained below, that causes the ball to curve. Another technique that aids a pitch's curve is arm contortion. A snapping motion in the elbow and wrist around or over the ball helps increase the pressure on the stitch and the total amount of spin and movement on the pitch.
Bernoulli Principle
It is the Bernoulli Principle that actually causes the ball to curve. The Bernoulli Principle holds that faster air streams have lower air pressure. When a curveball is thrown and the ball is spinning with its stitches pushing the air around it, the air around the ball becomes unbalanced. The side of the ball with slower air has higher pressure than the side of the ball with faster moving air, according to the Bernoulli Principle. The higher pressure on the slow-air side of the ball pushes the ball and causes the movement we associate with "curving."
Curveball Movement
Despite the name, not all curveballs actually curve horizontally. Curveball movement depends on the pitcher's throwing angle, ball speed, direction and the air pressure caused by the ball's spin. In other words, while some pitcher's curveballs move laterally, parallel to the ground, others' curveballs have vertical movement, perpendicular to the ground.
Left or Right
Even though most curveballs curve slightly across the pitcher's body -- so a right-handed pitcher's curveballs break to the left and a left-handed pitcher's break to the right -- some curve the "wrong" way. Sometimes referred to as screwballs, when a right-handed pitcher throws a ball that breaks in on a right-handed hitter, the same physical principles apply; it's the spin that's different. In these pitches, the pitcher releases the ball in such a way that the hand comes sideways over the ball -- spinning the ball's stitches counterclockwise for right-handed pitcher -- and the air pressure to the right of the ball is lesser than to the left of the ball. The ball is pushed, or "curved," right -- which looks like a wrong curve because onlookers are used to seeing the ball curve the other way.
Perception Vs. Baseball Curveball
Although softball curveballs undergo the same forces as baseball curveballs, perception can make a baseball curveball appear more drastic. These perceptions are affected by a couple of factors. First of all, the height of the baseball mound and the camera angle at which most baseball games are filmed, from above and behind the pitcher, exaggerate the movement of a baseball. Softball pitching mounds, on the other hand, are lower than baseball mounds. Secondly, softballs are roughly twice the size of baseballs, which again can make the baseball curveball appear more drastic. Lastly, since the softball pitcher stands closer to the softball batter, there is less time and space for the softball to curve.
Member Comments