Baseballs are more than just white leather and red stitches—they’re a marvel of engineering, balancing tradition with performance. For over a century, their construction has remained largely unchanged, yet subtle tweaks have sparked heated debates about their role in Major League Baseball’s (MLB) scoring spikes, especially the home run surges since 2015. Let’s crack open the baseball, explore its layers, and investigate whether its materials could be behind those towering home runs.
The Anatomy of an MLB Baseball
Every MLB baseball is a carefully crafted orb, designed to meet strict standards for consistency, durability, and performance. Understanding its components is key to unraveling whether changes in materials could explain the scoring spikes.
The Core: The Pill at the Heart
At the center of every MLB baseball lies the “pill,” a small sphere made of cushioned cork wrapped in two thin layers of rubber—one black, one red. This core provides the ball’s bounce and resilience, ensuring it can withstand the force of a 100-mph fastball or a home run swing.
Yarn Winding: The Binding Force
Surrounding the pill are layers of tightly wound yarn, typically a wool-polyester blend. These layers give the baseball its structure and elasticity, helping it maintain shape under intense impact while contributing to its flight characteristics.
The Cover: Leather and Stitches
The outer layer is made of cowhide, stitched with exactly 108 red cotton stitches. This leather cover provides grip for pitchers and durability for gameplay, while the stitches influence aerodynamics, affecting spin and trajectory.
Table: Baseball Components and Their Roles
| Component | Material | Purpose |
|---|---|---|
| Core (Pill) | Cork, black/red rubber | Provides bounce, resilience, and maintains shape under impact |
| Yarn Winding | Wool-polyester blend | Adds structure, elasticity, and contributes to flight distance |
| Cover | Cowhide, cotton stitches | Ensures durability, grip, and influences spin and aerodynamics |
The Home Run Surge: A Modern Mystery
Since the 2015 MLB All-Star Game, home run rates have skyrocketed, with 2017 seeing an all-time record of 1.26 home runs per game, compared to 0.86 in 2014. Fans, players, and analysts have pointed fingers at the baseball itself, suspecting it’s been “juiced” to fly farther. But is there evidence to support this, or are other factors at play?
A Personal Anecdote: The Suspicious Summer of 2017
I’ll never forget watching Aaron Judge crush a 495-foot home run in 2017. The ball seemed to defy gravity, soaring out of Yankee Stadium like a rocket. As a lifelong baseball fan, I couldn’t help but wonder: was it Judge’s raw power, or was something different about the ball? That season, home runs spiked dramatically, and the “juiced ball” theory gained traction.
The Juiced Ball Conspiracy
The idea of a “juiced” baseball isn’t new. Fans have long speculated that MLB tweaks balls to boost offense during low-scoring eras, hoping to draw bigger crowds. However, MLB and its sole manufacturer, Rawlings, have consistently denied intentional changes. So, let’s dig into the science to see if the materials hold clues.
Investigating the Materials: What’s Changed?
Studies since 2015 have revealed subtle but significant changes in baseballs that could explain the home run surge. Here’s what researchers have found.
Core Density: A Lighter Pill?
A 2018 study by the Keck School of Medicine and Kent State University used CT scans to compare baseballs from 2014/pre-2015 All-Star Game to those from 2017. They discovered a 56.7% decrease in core density in newer balls, with increased porosity observed via electron microscopy. A less dense core could reduce drag, allowing balls to travel farther when hit.
Improved Centering of the Pill
MLB Commissioner Rob Manfred admitted in 2019 that better centering of the pill might reduce drag. A poorly centered pill causes a ball to wobble in flight, increasing air resistance. Improved manufacturing precision could make balls fly straighter and farther, contributing to the home run spike.
Reduced Drag and Better Carry
A 2018 MLB-commissioned study by a team of physicists and statisticians found that post-2015 baseballs had lower drag coefficients, meaning they faced less air resistance. This “better carry” could add 5–10 feet to a fly ball’s distance—enough to turn a warning-track shot into a home run.
Table: Changes in Baseball Properties (2014 vs. 2017)
| Property | 2014/Pre-2015 ASG | 2017 | Impact |
|---|---|---|---|
| Core Density | Higher | 56.7% lower | Less drag, farther flight |
| Pill Centering | Less precise | More precise | Reduced wobble, less drag |
| Drag Coefficient | Higher | Lower | Better carry, increased distance |
Other Factors in the Home Run Surge
While changes in baseball materials are compelling, they’re not the whole story. Let’s explore other factors that could contribute to the scoring spike.
Stronger Players, Smarter Strategies
Today’s players are bigger, stronger, and trained with advanced analytics. Hitters now prioritize launch angle and exit velocity, aiming for fly balls that are more likely to become home runs. This “launch angle revolution” aligns closely with the 2015–2019 home run surge.
Pitching Changes
Pitchers are throwing harder than ever, with fastballs routinely exceeding 95 mph. Paradoxically, higher velocity can lead to harder contact when hitters connect, sending balls farther. Additionally, pitchers’ reliance on sliders and cutters may give hitters more predictable pitches to crush.
Pros and Cons of the Juiced Ball Theory
Pros:
- Scientific evidence shows changes in core density and drag.
- Improved pill centering reduces wobble, supporting longer flights.
- Home run spikes align with manufacturing changes post-2015.
Cons:
- MLB denies intentional juicing, citing manufacturing variability.
- Player strength and hitting strategies also contribute significantly.
- No conclusive evidence of deliberate tampering by Rawlings.
The Science vs. The Skeptics
The juiced ball theory has its skeptics. Kathy Smith-Stephens, Rawlings’ director of quality assurance, insists the manufacturing process hasn’t changed meaningfully. Yet, studies like the one published in ACS Omega (2019) suggest that even unintentional changes, like slight variations in core density, could have outsized effects on performance.
A Humorous Aside: The Tin Foil Hat Brigade
Some fans take the juiced ball theory to extremes, picturing MLB executives in shadowy boardrooms, plotting to supercharge baseballs for profit. While the conspiracy adds spice to barroom debates, the truth likely lies in mundane manufacturing tweaks rather than a grand scheme.
People Also Ask (PAA)
Here are answers to common Google queries about baseball composition and scoring spikes.
What Are Baseballs Made Of?
MLB baseballs consist of a cork-rubber core (the pill), wrapped in wool-polyester yarn, and covered with cowhide stitched with red cotton. Theseroses Each component is designed for durability, grip, and consistent performance.
Why Are There More Home Runs in Baseball Now?
Increased home runs since 2015 may result from changes in baseball core density, better pill centering, and reduced drag, alongside stronger players and strategic shifts toward fly-ball hitting.
Where Can I Buy Authentic MLB Baseballs?
Official MLB baseballs are available from retailers like Rawlings or sports stores like DICK’S Sporting Goods. Ensure authenticity by checking for the official MLB logo.
Are Baseballs Juiced in MLB?
While MLB denies intentional changes, studies show post-2015 baseballs have lower drag and less dense cores, which may contribute to increased home run distances.
What’s the Best Tool for Analyzing Baseball Performance?
For fans, tools like Statcast provide detailed data on exit velocity, launch angle, and ball flight, helping analyze performance trends.
Where to Get Authentic MLB Baseballs
If you’re a collector or aspiring player, authentic MLB baseballs can be purchased from trusted sources. Rawlings’ official website offers game-used and replica balls, while major retailers like Fanatics or local sports shops carry them too. Always verify the MLB logo to ensure authenticity.
Best Tools for Baseball Analysis
For those diving into the nitty-gritty of baseball performance, tools like Statcast offer real-time data on ball flight, spin rates, and player metrics. FanGraphs and Baseball-Reference provide in-depth stats for tracking trends like home run rates. For a hands-on approach, try swing trackers like Blast Motion to analyze your own hitting mechanics.
FAQ Section
Q: What materials make up an MLB baseball?
A: An MLB baseball has a cork-rubber core (pill), wool-polyester yarn windings, and a cowhide cover with 108 red cotton stitches, designed for durability and performance.
Q: Have baseballs changed since 2015?
A: Yes, studies show post-2015 baseballs have less dense cores and lower drag, which may contribute to increased home run distances, though MLB denies intentional changes.
Q: How do baseball materials affect gameplay?
A: The core’s density affects bounce and flight distance, yarn windings provide elasticity, and the leather cover and stitches influence grip, spin, and aerodynamics.
Q: Why do some baseballs fly farther?
A: Lower core density, better-centered pills, and reduced drag in newer baseballs can decrease air resistance, allowing balls to travel farther when hit.
Q: Where can I find data on home run trends?
A: Websites like FanGraphs and Baseball-Reference offer detailed stats on home run rates and player performance.
Conclusion: A Complex Puzzle
The surge in home runs since 2015 is a fascinating puzzle, with baseball materials playing a significant but not exclusive role. Subtle changes in core density, pill centering, and drag have likely contributed to balls flying farther, but player strength, smarter hitting strategies, and faster pitches also share the spotlight. As a fan, it’s thrilling to see more dingers, but the debate over “juiced” balls keeps the game’s science as gripping as a ninth-inning rally. Whether you’re a casual viewer or a stats nerd, understanding the baseball’s construction deepens your appreciation for America’s pastime.
Sources:
- C&EN: “What’s in baseballs, and can materials explain a spike in scoring?”
- CBSSports.com: “MLB reveals results of study on whether juiced balls led to home run spike”
- ACS Omega: “Physicochemical Investigation into Major League Baseballs”
- Larry Brown Sports: “Rob Manfred admits change in baseballs may be behind home run spike”