Introduction
In the age of high-velocity fastballs and wicked sliders, the screwball is a rare gem—a pitch shrouded in mystery and often misunderstood.
Its unique movement baffles batters, curves expectations, and challenges conventional pitching mechanics. But how do you throw a screwball effectively without damaging your arm? And why do so few pitchers use it today?
This guide demystifies the screwball and offers a comprehensive breakdown of the technique, the science, and the training needed to throw it safely and effectively.
What Is a Screwball?
A screwball is a type of baseball pitch that breaks in the opposite direction of a curveball. For a right-handed pitcher, it moves down and in toward a right-handed batter, creating deceptive movement that’s hard to track.
Key Characteristics
- Velocity: Typically slower than a fastball
- Movement: Breaks inside to same-handed batters
- Grip: Similar to a circle change-up
- Rotation: Reverse spin compared to curveballs or sliders
The History of the Screwball
The screwball isn’t new. It gained fame in the early 20th century, with pitchers like Christy Mathewson and Carl Hubbell using it to dominate their eras.
In more recent years, pitchers like Fernando Valenzuela and Hector Santiago kept the pitch alive. Despite its success, the screwball gradually faded due to concerns about arm strain and coaching philosophies favoring more conventional pitches.
Why Learn the Screwball?
Unique Advantages
- Unpredictability: Few hitters practice against screwballs
- Arm-side movement: Helps neutralize same-handed batters
- Change of pace: Alters the timing and rhythm of at-bats
Modern Use Cases
- Ideal for pitchers with average velocity
- Useful as a “change-of-pace” pitch in a diverse arsenal
- Helps high school and college pitchers stand out
How Does a Screwball Work?
The screwball’s unique movement results from reverse spin, caused by the pronation (inward rotation) of the pitcher’s forearm at release. This spin generates Magnus force, pushing the ball toward the pitcher’s arm side.
| Pitch Type | Spin Direction | Movement |
| Curveball | Top-to-bottom | Breaks down and away |
| Slider | Diagonal | Breaks across |
| Screwball | Inside (arm-side) | Breaks in and down |
Is It Bad for Your Arm?
Contrary to myth, the screwball can be safer than sliders or curveballs if thrown correctly. It emphasizes pronation, a natural motion that can reduce stress on the elbow compared to supination-based pitches.
How to Throw a Screwball
1. Master the Grip
The screwball grip closely resembles a circle change-up:
- Form a circle with your index finger and thumb
- Place the ball across your middle and ring fingers
- Rest your pinky on the side for balance
- Tuck the ball deeper into your hand to reduce velocity
2. Perfect the Arm Action
- Throw with your normal fastball arm speed
- At release, pronate your wrist (turn it inward)
- Avoid snapping the wrist like a curveball
3. Focus on Release and Follow-Through
- Release the ball slightly in front of your body
- Let the ball roll off your fingers for inward spin
- Follow through naturally with your throwing arm across your body
Key Drills to Improve Screwball Mechanics
A. Pronation Drill
- Throw a tennis ball using a screwball motion
- Focus on pronating the forearm without straining the elbow
B. Grip Pressure Drill
- Practice holding the ball with minimal pressure using your pinky
- Helps avoid squeezing too tightly and affecting control
C. Target Practice
- Place cones or markers inside the strike zone
- Aim to hit inner corners with a screwball trajectory
Common Mistakes and How to Avoid Them
1. Over-supination
Mistake: Turning wrist outward like a curveball
Fix: Practice pronation slowly to build muscle memory
2. Arm Slot Inconsistency
Mistake: Changing arm angle while throwing the screwball
Fix: Keep the same release point as your fastball for deception
3. Over-gripping the Ball
Mistake: Squeezing the ball too tightly
Fix: Relax your grip to allow for natural movement
Building a Screwball into Your Repertoire
Weekly Practice Plan
| Day | Focus |
| Monday | Dry mechanics (no throwing) |
| Wednesday | Light bullpen session (10–15 pitches) |
| Friday | Simulated game reps |
| Sunday | Review video, adjust grip/angle |
Strength and Flexibility
- Forearm and wrist exercises (e.g., wrist curls, rice bucket drills)
- Shoulder mobility routines
- Long toss and recovery protocols
Pro Tips from Coaches and Players
“Pronation is your friend. Most pitchers pronate naturally—it’s learning to control it that makes the screwball effective.”
— Pitching coach, Division I Baseball
“The key is arm speed. Don’t slow down like you’re throwing a curveball. The deception comes from the spin, not the speed drop-off.”
— High school varsity pitcher
When to Use a Screwball in a Game
- Against same-handed batters who are crowding the plate
- As a second strike pitch to induce ground balls
- In two-strike counts for strikeouts via misread
Strategic Pitch Sequence Example
- Fastball outside
- Slider away
- Screwball inside (strikeout pitch)
Alternatives to the Screwball
If the screwball feels unnatural or ineffective, consider:
- Circle change-up: Similar movement, easier to learn
- Sinker: Downward movement with higher velocity
- Splitter: Late drop, works well in tandem with fastballs
Conclusion
The screwball may not be mainstream today, but it offers a unique advantage to pitchers who master it. With proper mechanics, safe training, and strategic deployment, it can become a valuable tool in your pitching arsenal.
Whether you’re a youth player, high school ace, or weekend warrior, adding the screwball can help you stand out and keep hitters guessing.
FAQs
Q1: Is throwing a screwball bad for your arm?
No, if thrown correctly. It uses pronation, which is safer than the supination used in breaking balls like curveballs or sliders. Proper form and conditioning are key.
Q2: What’s the difference between a screwball and a change-up?
A screwball breaks arm-side with spin-induced movement, while a change-up reduces speed to disrupt timing without as much lateral break.
Q3: Why don’t MLB pitchers use the screwball more?
There’s a belief (not fully supported by evidence) that it increases injury risk. Many coaches prefer to teach pitches with more data and usage in today’s game.
Q4: Can youth pitchers throw a screwball?
Yes, but with caution. It should be introduced only after fastball and change-up mechanics are solid, and under the guidance of a coach.
Q5: Does the screwball really break the opposite way of a curveball?
Yes. A right-handed curveball breaks down and away from right-handed batters; a screwball breaks inward and down.
