HISTORY114 - The History of MLB Bats

My previous blog was about the science of baseball’s home runs, the complex interplay of physics, aerodynamics, and even the environment, including the key factors that affect home run distance, and how home run distance is measured today.  I promised a second article on, “What is all the ruckus about torpedo bats, that are supposed to increase a batter’s home run proficiency?”  After starting the second article (this one), I decided that a discussion of torpedo bats (not introduced baseball until 2024), required a discussion of the history of Major League Baseball (MLB) baseball bats to put the objectives and design of the torpedo bat into prospective. 

This blog will include the history of MLB baseball bats, a summary of MLB specifications for bats today, a snapshot of what kinds of bats are used by MLB players today, and finally a discussion of the new torpedo bats.  I’ll conclude with a brief look at the future of bats.

I will list my sources at the end.

 

Background

The game of baseball was formalized in the U.S. in the mid-1800s, having evolved from earlier bat-and-ball games.  The first official baseball game with a published set of rules was played in 1846 between the New York Knickerbockers and the New York Nine.

The Cincinnati Red Stockings, formed in 1869, are considered the first all-professional baseball team.  MLB was officially formed in 1903 with the merger of the National League (NL) and the American League (AL).  The NL was founded in 1876, and the AL in 1901, but they operated independently until their 1903 merger.

 

History of MLB Baseball Bats

Early baseball players crafted their own bats from scrap wood, often using wagon wheel spokes, ax handles, or even tree branches.  Without size restrictions, bats varied widely in length and weight, sometimes exceeding 42 inches and 50 ounces.  Hickory was a common wood, but other types were also used.  Players experimented with flat bats, short bats, and fat bats, seeking any advantage they could gain.  However, players soon discovered that a round bat provided a better point of contact with the ball, leading to the gradual standardization of this shape.  As the game grew in popularity, the need for more consistent and standardized equipment became evident.

In 1859, the first rule limiting the diameter of a bat was introduced, specifying a maximum of 2.5 inches.  Further regulations in 1869 set a maximum length for bats at 42 inches, still in effect today.  Ash gradually replaced hickory as the wood of choice for baseball bats due to its lightness and flexibility. 

These regulations, though initially basic, paved the way for professional bat makers who prioritized consistency and durability.  Craftsmen utilized lathes and specialized tools to produce bats with greater precision and consistency, experimenting with different woods to find the ideal combination of strength, durability, and performance.

A pivotal moment in bat history occurred in 1884 when the Hillerich & Bradsby company of Louisville, Kentucky, crafted a custom ash bat, also known as "The Louisville Slugger,” for the Louisville Eclipse's star player, Pete Browning.  This marked a shift towards standardized, high-quality bats. 

Not getting the word about the movement to standardized bats, in 1890, Emile Kinst was awarded a patent for an “improved ball-bat, … which shall produce a rotary or spinning motion of the ball in its flight to a higher degree than is possible with any present known form of ball-bat, and thus to make it more difficult to catch the ball, or if caught, to hold it, and thus further to modify the conditions of the game… .”

 

In 1890, Emile Kinst was awarded a patent for a banana bat.

Later, in the 1890s, the maximum permitted diameter of a bat barrel was increased to 2.75 inches.  Bats could no longer be sawed off (flat) at the end, and the end of a bat was required to be rounded.  It was made illegal to use bats with a flat surface at the end, making rounded bats the standard. This change aimed to ensure fair play and potentially reduce a batter's ability to manipulate the ball's direction through flat surfaces, which were sometimes used for bunting.  These new rules standardized bat design and helped solidify the fundamental shape of wood bats used in professional baseball.

Early 20^th-century bats typically had thick handles, but tapered handles became more popular as players recognized they could improve swing speed.

By the early 1930s, ash emerged as the preferred wood for MLB bats, due to its strength-to-weight ratio.  (Towards the end of the century, maple bats began to gain popularity; maple is harder and denser than ash, contributing to increased performance.)

Cupped bats, with an indentation (cutout) at the end of the barrel, were formally approved by MLB in 1975.  Cupping lightens the bat and shifts the center of gravity.  By removing weight from the end of the barrel, it can make the bat feel more balanced and easier to swing, potentially increasing bat speed and control.

Cupped bats were approved by MLB in 1975.

 

Aluminum bats were introduced in the 1970s, driven by the desire for a bat that wouldn't splinter as easily as wood, and offering increased power and durability compared to wooden bats.  And composite bats emerged in the 1980s, made of materials like carbon fiber and resin, also stronger and capable of generating higher ball exit velocities compared to wooden bats.  But both aluminum and composite bats were banned from MLB in the early 2000s due to concerns about excessive power and safety. 

In the early 2000s, maple and ash were the most common types of wood used in MLB bats.  Bats had become more specialized, with varying barrel diameters, tapers, and knob shapes to suit different player preferences and hitting styles (subject to MLB bat specifications; see below).  Players and manufacturers constantly sought to improve bat performance, leading to advancements in materials and design. 

In 2010, MLB reduced the maximum bat barrel diameter from 2.75 inches to 2.61 inches.  This change was implemented primarily for safety reasons, specifically to reduce the risk of bats breaking into pieces during game play.  The older, larger bats were found to be more prone to breakage, potentially causing injury to players and others on the field.

Key elements of a modern traditional MLB bat.

 

Specifications for MLB Bats Today

Here's detailed breakdown of specifications for MLB bats today:

Material: MLB bats must made of solid wood, typically maple, ash, or birch. 

Shape: They must be round and smooth. 

Diameter: The maximum diameter is 2.61 inches. 

Length: The maximum length is 42 inches. 

Handle: The bat handle, extending from the knob, may be covered or treated with certain materials to improve the grip, but this treatment cannot extend more than 18 inches from the end of the bat handle.  Acceptable grip materials include cork, tape (excluding smooth, plastic tape), or commercially manufactured composition material.  Resin, pine tar, or drying agents can be used on the grip to enhance the hold.

Bat Knob: The primary function of a baseball bat knob is to prevent the bat from slipping out of a hitter's hands during the swing.  The bat knob must protrude from the handle.  The knob doesn't necessarily have to be part of the “solid piece of wood” that the bat is fashioned from. The knob can be permanently fastened or molded, lathed, or welded.  MLB bat knobs are primarily made of wood, specifically maple, ash, or birch.  While wood is the standard, some players use knobs made from other materials or incorporate attachments that affect the knob's shape or size. 

Cupped Bats: Bats can have an indentation in the end, up to 1¼ inch deep, 2 inches wide, and 1 inch in diameter.  The indentation must be curved with no foreign substance added. 

No Laminated or Experimental Bats: Laminated or experimental bats are not permitted until approved by the Rules Committee. 

Colored Bats: Colored bats are not allowed unless approved by the Rules Committee. 

No Specific Weight Restriction: There is no specific weight restriction for MLB bats. 

Logo and Finish: Approved manufacturer logos are required, and the finish is generally unregulated, although matte finishes are common. 

 

Bats Used by MLB Players Today

MLB players today use bats that reflect a balance between tradition and adherence to strict regulations, based on personal preference.  Players can customize the bat characteristics shown below, as long as the bat adheres to MLB standards.  Bats can be inspected by umpires before, during, or after a game to ensure they meet specifications.

Composition: Most bats are made of maple, but ash and birch are also used. 

Length: Bats are typically 33-34 inches long. The shortest bat used in MLB history was a 32 ¼ -inch bat used by Tony Gwynn. Yunel Escobar, a former MLB third baseman, swung a 36-inch bat.

Weight: While there's no weight limit, most MLB players use bats weighing between 31 and 34 ounces.  Historically, heavier bats were common, but lighter bats are now favored for bat speed.

In case you were wondering, Aaron Judge uses a 35-inch, 33-ounce bat made of maple.  And Shohei Ohtani uses a 34.5-inch maple bat that weighs 32 ounces.

Aaron Judge uses a 35-inch, 33-ounce maple bat.

Barrel Diameter: Most players do not use bats with a (max allowed) 2.61-inch barrel.  2.5 to 2.53 inches would be considered a "really big barrel" in today's game.  Some bats have barrels as small as 2.45 inches. 

Barrel Shape: Bat makers strategically distribute the weight through different areas along the bat to fit that player’s specifications for feel and performance.  The most notable recent development is the "torpedo bat," which shifts the bat's weight distribution closer to the hands.  This design aims to increase contact and bat speed, even though it may make the bat look unusual.  See below.

Handle Style: The "axe bat," with its ergonomic handle designed to improve grip and reduce wrist injuries, has gained popularity among some MLB players.  An axe bat has no knob at the base of the bat.  It’s also not perfectly round at the bat handle.  It has a flared, tapered handle that was designed to ease the pressure on hands and even prevent injuries.  Advocates claim better bat control and more efficient power transfer compared to traditional bats with round knobs and handles.

An axe bat knob compared to a traditional bat knob.

 

The Torpedo Bat

A "torpedo bat" is a bat with a non-traditional barrel shape.  It features a thicker barrel nearer to handle, where players said they more often hit the ball, and a thinner barrel end.  This design shifts the "sweet spot" (see below) closer to the hitter's hands, potentially increasing contact and power. 

Aaron Leanhardt, a former physicist at the Massachusetts Institute of Technology, now the Yankees’ major league analyst, developed the idea while working as the Yankees' assistant Minor League hitting coordinator from 2022-2023. 

New York Yankees' slugger Giancarlo Stanton used a torpedo-style bat to crush seven home runs in 14 postseason games during the Yankees' 2024 run to the World Series.  Following that success, torpedo bat models were made available to Yankees players during spring training in 2025, and on Opening Day, five members of the starting lineup used the bat to crush a combined nine home runs.

Torpedo bats are relatively new, and their long-term impact on baseball is still being evaluated.  Here are some MLB players who've used a torpedo-style bat so far this season:

• Elly De La Cruz, SS, Cincinnati Reds
• Jose Trevino, C, Cincinnati Reds
• Adley Rutschman, C, Baltimore Orioles
• Dansby Swanson, SS, Chicago Cubs
• Nico Hoerner, 2B, Chicago Cubs
• Ryan Jeffers, C, Minnesota Twins
• Francisco Lindor, SS, New York Mets
• Cody Bellinger, OF, New York Yankees
• Jazz Chisholm Jr., 2B, New York Yankees
• Paul Goldschmidt, 1B, New York Yankees
• Anthony Volpe, SS, New York Yankees
• Austin Wells, C, New York Yankees
• Junior Caminero, 3B, Tampa Bay Rays
• Davis Schneider, OF, Toronto Blue Jays

The Sweet Spot on a Bat. The "sweet spot" on a baseball bat is the area where the bat's vibrations are minimal, and the ball's energy is transferred most efficiently to the bat, resulting in a powerful hit with minimal stinging sensation to the hitter's hands. This area is typically located around 5 to 7 inches from the end of the barrel on a standard MLB bat.

The Torpedo Bat Design. The torpedo bat design aims to optimize the location of the sweet spot, based on analysis of a player's hitting tendencies.  By concentrating more weight and mass in the area where a player consistently hits the ball, the torpedo maximizes the energy transferred to the ball during contact.  This redistribution of weight may also influence the bat's swing weight, potentially allowing players to swing faster and harder. 

Note:  The torpedo bat is legal; it fits within current MLB’s specifications for bats.

The torpedo bat shifts the "sweet spot" closer to the hitter's hands, where he consistently hits the ball, increasing contact and power. 

The Future of Baseball Bats

The future of baseball bats is trending towards personalized, data-driven designs, and potentially further material advancements, with a focus on optimizing performance for individual players.  Data analytics are allowing for the creation of bats tailored to a player's unique swing and hitting preferences, potentially maximizing their performance.  Furthermore, technology continues to drive innovation in the world of baseball bats.  Computer-aided design and advanced manufacturing techniques will enable the creation of bats with optimized weight distribution and performance characteristics.  There's even potential for future "smart bats" equipped with sensors to track swing data and provide real-time feedback for players.

 

 

"I never blame myself when I'm not hitting.  I just blame the bat and if it keeps up, I change bats." - Yogi Berra

 

 

Sources

My principal sources include: “Baseball bat,” Wikipedia.com; “The History of the Baseball Bat,” phoenixbats.com; “3.02 The Bat,” baseballrulesacademy.com; “The Physics of the Torpedo Bat,” blog.fangraphs.com; plus, numerous other online sources.  I am increasingly, and hopefully carefully, using Google’s AI/ChatGPT summaries of searches, including for this blog “history of MLB bats,” “why was the max diameter of bats changed,” “variation in MLB bats today,” “what is the sweet spot on a baseball bat,” “specifications for MLB Bats,” “motivation for torpedo bats,” “torpedo bats vs. regular bats,” and “the future of baseball bats.”  These AI summaries directed me to numerous additional specific sources.