Pitchers love to get batters out. One of the most satisfying ways to get a batter out is to get them swinging, especially fooling them with a curveball. Unfortunately, pulling that off requires a great deal of skill and other good pitches to set it all up. We will explain the difference between a curveball and fastball pitch in baseball and why young pitchers should not rush to try to develop a curveball before they reach adolescence and have a high level of control of speeds and pitch locations with the fastball, change-up, and slider.

A fastball is the easiest pitch to throw because it has the most efficient and natural release. The pointer and middle fingers push directly off the back of the ball in the direction of the target. The downward and forward push of these fingers gives the ball the most ball speed possible with some backward spin. The speed of the fastball and its tendency to drop less because of the backspin makes this pitch difficult to hit.

Hand and Finger Position for a Fastball

The natural downward wrist motion (flexion) and inward forearm rotation (pronation) at release are very important for generating ball speed. (You can read about these terms at http://www.med.umich.edu/lrc/Hypermuscle/Hyper.html.) These arm actions are also important because they continue after release and gradually slow down to prevent injury to your arm. Remember that your hand is moving very fast after release and must gradually slow down to prevent injury.

Wrist Flexion and Extension

A curveball requires just as much hand speed as a fastball and uses the same wrist and forearm motions as a fastball. Unfortunately, these wrist and forearm actions are timed slightly different to get the fingers pushing forward and downward off the top of the ball. This different hand position at release creates a forward and sideward ball spin that makes the ball drop.

The Curveball Drops Lower Than the Fastball

You can read about how spin creates a force in the air that creates this curve at www.ithaca.edu/faculty/sigg/baseball.htm and wings.avkids.com/Tennis/Book/magnus.html. Coaches often use the cue "pull a shade" to throw a curveball because the fingers forward action is similar to pulling on the strings of a shade.

Hand and Finger Position for a Curveball Near Release

It is very important for players and coaches to realize that the curveball has the same forearm and wrist release motions (pronation & flexion), but it must be precisely timed and delayed to push off the top of the ball. Some people incorrectly believe the curveball is created by the opposite forearm action (supination or turning your palm upward). Because the hand position at release in the curveball is less natural it has less shock absorbing range of motion to slow down the hand and arm. Let's look at the four main reasons why it is better for young pitchers to not be in a hurry to develop the curveball.

The first reason to avoid throwing curveballs early in your pitching development is that the spin needed to make pitches curve decreases the speed of your pitches. The off-center push of the fingers on the ball to make spin, comes at a cost of ball speed. A typical major league curveball is thrown at 80 to 85% of the speed of the fastball. The slower speed of the curveball makes it easier to hit if the batter is not fooled (is expecting a curveball).

The second reason is related to the lost ball speed because it is important for young pitchers to realize that curveballs do not always work (break and fool a hitter). It only looks that way when some very young pitchers have a good curveball and strike out batters who have not seen curves and are easily fooled. Most of your early curveball pitches will not have enough topspin and will be very easy to hit. If the pros occasionally "hang" a curveball, imagine how many cream puffs you will be throwing over the plate for batters to crunch. Remember, in the real world the curveball is not a magic pitch that gets them swinging every time.

The third reason is related to the concerns of sports medicine professionals that throwing the curveball places unnatural (uneven) stresses on the arms of pitchers. The extra wrist motion in the curveball (complicating wrist motion and loading) is called ulnar deviation (tilting your hand sideways toward your little finger). These motions and stresses on pitcher's arm are large and dangerous since a skilled pitching action transfers large amounts of energy to the arm from the larger muscles of the legs and trunk. Repetitive loading is an important concern for young pitchers because the growth plates of their bones have not closed. The muscles, bones, and ligaments of young pitchers are not as strong as an adult pitcher. Biomechanical studies show that the upper extremity loads in young pitchers are quite large and then get larger with age and experience⁷. The smaller joints and muscles of the arm are prone to injury because of overuse or inadequate rest. It's important for young pitchers to not throw more than 90 full speed pitches in any outing, game or practice² and take a couple days off before pitching. Recent recommendations from sports medicine experts encourage rules changes based on pitch count rather than the traditional number of innings pitched. Andrews and coworkers¹ recommend fewer pitches per outing for younger pitchers (between 50 -70), gradually increasing to 100 pitches by ages 17 and 18. They point out that the two days of rest should include not playing positions requiring many long throws (3rd and short) on off days.

Maybe the most important reason for the pitcher to wait to learn the curveball is that they could easily mess up their other pitches. The very small differences in grip, finger pressure, and hand position at release in the curveball make it very difficult to master. It is likely that a young pitcher learning a curve will go through a period of time where this interferes with their other pitches. Most of pitching success is pitch location, speed, and messing up the timing of the hitter. A young pitcher is more likely to get more hitters out by working on accuracy, fastball variations, a change-up, and other pitches with more natural release actions. Why be in a hurry to work on a pitch that is harder to throw and harder on your arm, especially when it could mess up your other pitches and be easier to hit? The next section will tell you how to throw easier pitches that break and suggest when it might be wise to work on a curveball.

Unfortunately, there is not easy answer that is appropriate for all young pitchers. Most players and coaches know from experience that the age of a player is often very different from their physical (physiological) age. Some players might remember playing in a 10 year old league against a giant with a 13 year old body. Rather than focus on age, the young pitcher or coach should focus on physical and pitching development. Youth baseball coaches are encouraged to not let children under 10 years old pitch, and to not begin curveball pitching until after physical maturity⁴ or about age 14¹. A pitcher might start seriously working on a curveball in the off-season if they can answer yes to the following five questions.

1. Do I have good, consistent pitching mechanics?
2. Do I have consistent control of easier pitches (fastball, change-up, slider)?
3. Do I have parental or coaching assistance to help me?
4. Will I consistenly practice with proper warm-up, technique, and adequate rest?
5. Will I continue other physical activities to improve my conditioning?

Since an honest answer from most young pitchers will not quite total five "yes" answers, here is a progression of pitching development leading to throwing curves.

The first pitching variation youth coaches suggest working on are changes in speed ^1,4 and fastball variations. Young pitchers can than get used to different grips and finger pressures. Throwing a two seam fastball will tend drop more than a four seam fastball. The classic and "OK" grips allow young pitchers to learn the change-up easily and safely⁴. The pitching and release actions are similar to the fastball. If the pitcher has an impressive fastball, the occasional change-up is a great pitch to fool hitters.

Hand and Finger Position for a Change-up

One of the easiest breaking balls to learn is the slider and it has many advantages for the pitcher. The slider has a fastball-like grip and release position and still travels rather fast (90% of a fastball). A right handed pitcher aligns both fingers to the right of the center of the back of the ball. The normal downward and forward push of the fingers puts a side spin on the ball that makes it break to the left. The good pitcher aims the slider from the center to the outside of the plate against a right-handed hitter so the ball curves out of their effective reach.

Hand and Finger Position for the Slider

The smart young pitcher does not rush to look like the pros since their skills and bodies are not ready for it. The young pitcher will get more hitters out, have a longer career on the mound, and make the all star team more easily if they master control of a few pitches. More pitches can only be added when there is control of the basic pitches that set up a good curveball.

1. Andrews, J.R., Flesig, G.S., & Witeside, J.A. (1999). Little leaguer's elbow: evaluation, treatment, and prevention. Sports Medicine Update, 14(3), 11-15.
2. Andrews, J.R. & Flesig, G.S. (1998). Preventing throwing injuries. Journal of Orthopaedic and Sports Physical Therapy, 27, 187-188.
3. Cicantelli, P. (1994). Avoid elbow pain: tips for young pitchers. Physician and Sportsmedicine 22(3), 65-66.
4. Clark, M.A. (1993). Curve balls: do they have a place in youth baseball? Spotlight on Youth Sports, 16(1), 2-4.
5. Congeni, J. (1994). Treating--and preventing--little league elbow. Physician and Sportsmedicine 22(3), 54-64.
6. Duda, M. (1985). Prevention and treatment of throwing-arm injuries. Physician and Sportsmedicine, 13(6), 181-186.
7. Flesig, G.S. et al. (1999). Kinematic and kinetic comparison of baseball pitching among various levels of development. Journal of Biomechanics, 32, 1371-1375.

Sport Science is an interactive study of sports designed to help students understand aerodynamics, physics, and mathematics, as part of NASA's educational outreach mission via the World Wide Web.