Why Softball Pitchers Throw Underhand Rules Technique

Softball is often mistaken for a gentler version of baseball, but beneath its seemingly relaxed exterior lies a sport rich in strategy, athleticism, and distinct mechanics. One of the most defining characteristics of the game is the underhand pitching motion. Unlike baseball’s over-the-top delivery, softball pitchers are required to throw underhand—a rule that defines not only the style of play but also the physical demands and tactical nuances of the sport. Understanding why this rule exists, how it influences technique, and what advantages it brings reveals much about softball’s identity and evolution.

The Origins of Underhand Pitching

Softball was invented in 1887 as an indoor variant of baseball, originally called “mushball” or “kitten ball.” The early versions were played in confined spaces like gymnasiums, where overhead throws posed a risk to walls, ceilings, and spectators. To accommodate these limitations, players adopted a low, underhand throwing style that minimized arc and velocity while maintaining control. This practical adjustment became codified into official rules as the sport formalized in the early 20th century.

By the 1930s, standardized rules established the underhand delivery as mandatory. The Amateur Softball Association (ASA), now USA Softball, institutionalized the requirement to ensure consistency and fairness across leagues. Over time, what began as a spatial necessity evolved into a core element of the game’s identity—distinguishing it from baseball and shaping its unique rhythm and challenges.

Official Rules Governing Pitching Mechanics

The current USA Softball Rulebook specifies strict guidelines for legal pitches. According to Rule 6, Section 4:

• The pitch must be delivered underhand.
• The arm must move in a single, continuous motion, with no backward rotation past the hip.
• The pivot foot must remain in contact with the pitcher’s plate until the ball is released.
• The ball must be released below the hip, and the hand must not rise above the knee at any point during the backswing.

These rules are enforced to preserve the integrity of the underhand style and prevent pitchers from mimicking baseball-style deliveries. Violations result in an illegal pitch, which awards the batter a ball or allows base runners to advance, depending on the situation.

Tip: Coaches should regularly review pitching form with slow-motion video analysis to ensure compliance with release height and arm path regulations.

Technique and Biomechanics of Underhand Pitching

Despite appearances, underhand pitching is far from simple. Elite pitchers generate significant speed and movement through precise coordination of the legs, hips, torso, and arm. The windmill pitch—the most common technique in fastpitch softball—involves a full circular arm motion that begins behind the body and ends with a powerful snap at release.

The kinetic sequence follows a whip-like chain:

1. Leg drive: The push off the rubber generates forward momentum.
2. Hip rotation: As the stride foot lands, the hips open rapidly, transferring energy up the body.
3. Shoulder torque: The upper body lags slightly, creating tension that amplifies force.
4. Arm acceleration: The arm completes the windmill circle, releasing the ball at speeds exceeding 60 mph in elite circles.

This technique reduces stress on the shoulder compared to overhand throws, though it places unique strain on the elbow and biceps tendon. Proper mechanics are essential to prevent injury and maximize efficiency.

“Underhand pitching isn’t less athletic—it’s differently athletic. The windmill motion requires explosive power, timing, and endurance comparable to any high-level sport.” — Dr. Linda Chen, Sports Biomechanist, University of Michigan

Safety and Game Balance Considerations

One of the primary reasons underhand pitching remains standard is player safety. In youth and recreational leagues, where reaction times vary widely, the flatter trajectory and generally lower velocity of underhand throws give batters more time to respond. This helps reduce the risk of serious injury from line drives or wild pitches.

Additionally, the underhand delivery contributes to competitive balance. Because pitchers cannot rely on extreme vertical drop or overpowering speed in the same way as baseball hurlers, success depends more on precision, variation, and deception. This levels the playing field and emphasizes skill development over raw power.

Consider this comparison between baseball and softball pitching dynamics:

Aspect	Baseball (Overhand)	Softball (Underhand)
Average Pitch Speed	85–100 mph (pro)	55–70 mph (elite)
Release Point Height	6–7 feet	3–4 feet
Pitching Distance	60.5 feet	43 feet (fastpitch)
Reaction Time for Batter	~0.4 seconds	~0.35 seconds
Primary Stress Areas	Shoulder, UCL	Elbow, biceps tendon

Despite the shorter distance, the reduced reaction window in softball—due to faster perceived speed and sharper break on pitches—makes hitting exceptionally challenging. This paradox underscores how technique compensates for mechanical constraints.

Common Misconceptions About Underhand Throwing

Many assume underhand pitching is easier or less intense than overhand. This misconception overlooks the rigorous training, repetition, and physical toll involved. Pitchers routinely throw 100+ pitches per game and may log thousands weekly during peak seasons. The repetitive nature of the windmill motion increases susceptibility to overuse injuries if not managed carefully.

Another myth is that underhand limits pitch variety. In reality, skilled pitchers throw a wide array of pitches—including rise balls, curveballs, screwballs, drops, and changeups—each designed to deceive the hitter through spin and trajectory. Mastery of these variations requires deep understanding of grip, wrist action, and release point control.

Step-by-Step Guide to Learning the Windmill Pitch

For aspiring pitchers, developing a consistent underhand delivery involves progressive skill building. Here’s a structured approach:

1. Master the stance: Stand sideways to the plate, feet shoulder-width apart, with the pivot foot on the rubber.
2. Initiate the wind-up: Begin with a controlled backswing, keeping the glove hand in front and the throwing arm moving in a smooth arc.
3. Drive off the rubber: Push forcefully with the back leg while beginning hip rotation.
4. Stride forward: Extend the front leg toward the plate, landing on the heel with the toe angled outward.
5. Rotate hips and shoulders: Uncoil the torso so the hips lead the shoulders by about 45 degrees.
6. Complete the arm circle: Whip the arm forward in a tight circle, releasing the ball just below the hip.
7. Follow through: Allow the arm to continue upward across the body, finishing near the opposite shoulder.

Repetition with attention to form is key. Beginners should start at half-speed and gradually increase intensity as muscle memory develops.

Tip: Use resistance bands to strengthen rotator cuff muscles and improve arm speed without compromising joint health.

Real-World Example: Monica Abbott’s Record-Breaking Career

Monica Abbott, one of the most dominant pitchers in softball history, exemplifies the power and precision possible within the underhand framework. In 2010, she threw a pitch officially clocked at 77 mph—the fastest recorded in women’s collegiate softball. Her success stemmed not from brute force alone, but from flawless mechanics, relentless conditioning, and an arsenal of deceptive pitches.

During her tenure at the University of Tennessee, Abbott amassed over 2,400 strikeouts and led her team to multiple Women’s College World Series appearances. Even after retiring from collegiate play, she continued dominating professionally in Japan and the National Pro Fastpitch league. Her career illustrates how the underhand rule does not limit excellence—it channels it into a specialized, highly refined discipline.

Frequently Asked Questions

Can softball pitchers ever throw overhand?

No. Underhand delivery is mandatory in all sanctioned forms of softball, including fastpitch and slowpitch. Any overhand or sidearm motion that violates the arm swing or release height rules is considered illegal.

Why don’t softball pitchers throw faster than baseball players?

While peak velocities are lower, the shorter pitching distance (43 feet vs. 60.5) means the ball reaches the batter nearly as quickly. Additionally, biomechanical differences limit top-end speed, but advanced techniques compensate with movement and timing disruption.

Is underhand pitching safer for young athletes?

Generally, yes. The underhand motion produces less shoulder torque than overhand throwing, reducing the risk of labrum or UCL injuries common in youth baseball. However, elbow and forearm strains can still occur without proper mechanics and rest.

Final Thoughts and Call to Action

The underhand pitch is more than a rule—it’s the heartbeat of softball. It shapes how the game is played, who excels at it, and how fans experience its drama. From its origins in cramped gymnasiums to Olympic stadiums, the underhand throw has proven both resilient and revolutionary.

Whether you’re a player refining your windmill, a coach teaching fundamentals, or a fan seeking deeper appreciation, understanding the rationale behind underhand pitching enriches your connection to the sport. Respect the rules, study the technique, and recognize the athleticism it demands.

🚀 Ready to improve your pitching game? Break down your mechanics, consult a certified instructor, and commit to deliberate practice. Share this article with a teammate or coach to spread knowledge and elevate the next generation of softball talent.