As a former pitcher, my baseball specialty is pitching. Previously I wrote about the changeup, and in continuing the series on different pitches, I will now focus on the curveball. First it is important to rectify one glaring misconception about the curveball. Despite its name, a curveball rarely curves. The closest pitch that comes to curving is a slider, but it is better described by its given name because it slides across the plate. When I was younger and I mentioned throwing a curveball, those adults in my life who thought they understood baseball would tell me that one throws a curveball by snapping their wrist when throwing the pitch. Sadly, yet not surprisingly, these self-determined "baseball experts" had it all wrong. The wrist snapping motion will produce something closer to a slider or possibly a “slurve” (in between a curveball and slider). A slider is not only difficult to throw, but also a dangerous pitch for a young pitcher to throw, whose body hasn't fully developed.
A true curveball has a 12-6 motion. Imagine a clock, with 12 o'clock at the top and 6 o'clock at the bottom. A curveball loops from the top of the strike zone (12 o'clock) to the bottom of the zone (6 o'clock). It is classified as a breaking ball because the pitch literally has a breaking point—the point at which the ball drops from the 12 o'clock position. Curveball speeds can vary depending on the pitcher's strength, arm speed, and mechanics. An average major league curveball clocks in between 70 and 83 mph. Given that the average fastball speed is 90 mph, a curveball constitutes a solid difference in velocity, something a pitcher needs to be effective.
A classic curveball grip has the pitcher find the backwards "C" on the ball that is created by the seams and place his pointer finger and middle finger side-by-side with the pointer finger on the top seam that makes up the "C". Next the thumb is placed seam on the bottom of the ball. The ring finger and pinky finger are curled under and away from the ball. While gripping a curveball is simple, throwing the pitch correctly takes much practice and concentration.
The curveball, unlike the changeup, has a specific arm motion attached to it. If a pitcher takes his arm with the back of the hand facing up, and then turns the arm 90 degrees clockwise as if to give the thumb's up sign, he is ready to throw the ball. Using the aforementioned grip, he throws the curveball with a chopping arm motion while simultaneously letting the ball roll off his fingers so as to create a tight spin. Look at the arm motion involved in throwing a curveball in this slow motion shot. Notice the chopping motion and the way Lincecum holds the ball; they are both classic curveball attributes. This spin and grip cause the ball to arc in a parabolic motion. If thrown improperly, the ball may sail on the pitcher or sometimes land in front of the plate. Controlling the curveball isn't easy and takes practice.
Mastering the curveball can instantly improve a pitcher's abilities on the mound. When I first began throwing the curveball I could not throw it consistently for a strike, but I used it as an 0-2 or 1-2 count pitch in order to strike out the hitter. In those situations the curveball is best thrown so that the ball appears to be a strike but then, because of the spin, breaks out of the strike zone and lands below the knees of the hitter. Hitters will see a ball that looks to be slower and in the strike zone but instead ends up at their feet, thus causing them to swing over the pitch. Eventually, I learned as most pitchers do, to throw the curveball for a strike, improving my pitching abilities even more. Hitters adapt to the pitching they face. If a pitcher does not learn to throw the curve for a strike, hitters will recognize the curveball, will know it will be a ball, and refrain from swinging.
Most high school and college pitchers throw the curveball, but many abandon it in favor of the slider because a slider can be thrown with greater velocity, and can be easier to throw for a strike. Nonetheless, many major league pitchers who throw curveballs do so with great success. Felix Hernandez, Adam Wainwright, and Tim Lincecum throw three of the best curveballs currently in the majors. Historically, no one threw a better curveball than Sandy Koufax. His legendary curveball earned him Hall of Fame status. In this video, Cliff Lee demonstrates the effectiveness of a curveball. Start watching the video at the 30 second mark and watch until the 50 second mark. Within those 20 seconds, Lee displays a great looping curveball. There he is throwing the pitch to a right handed hitter, but when a pitcher is facing a hitter who hits from the same side that the pitcher throws, a breaking ball such as a curveball can be devastating and unhittable.
So, to recap, a curveball is a breaking ball that doesn't actually curve, but instead loops from 12 o'clock to 6 o'clock. It is a good pitch for a young teenager to learn and add to their repertoire. Major-leaguers use it by playing it off of the fastball due to the curveball's difference in speed and its break.