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Distance Between Bases – Baseline Measurements

  • The standard distance between bases in Major League Baseball, College and High School is 90 feet
  • For youth baseball, the distance can be 40 feet to 90 feet, depending on the age level and specification outlined by the affiliated national youth baseball league
distance between bases - baseline measurement layout

As a seasoned youth baseball coach, I’ve seen firsthand how the measurement tape becomes the unsung hero of baseball.

You see, the essence of baseball – the exhilarating race to first base, the daring steal to second, the clutch slide into third, and the triumphant dash to home – is all dictated by the 90-foot baseline.

This 90 feet is the standard distance between bases in Major League, College, and High School baseball, but let me tell you a little story about an eager, young team I once coached, the “Little Pioneers,” as they called themselves. These kids, merely 7 and 8 years old, were cool to play on a “big field”.

Needless to say, their early games looked more like marathons. Exhausted runners barely made it halfway to first base, fielders struggled with massive gaps to cover, and of course none of them could make the throw to get the runner out. It truly was a spectacle!

When we switched over to a smaller, 46/60 field, the transformation was magical: kids were hitting more, getting on bases in time, scoring more runs, more plays at the bases, and, most importantly, more smiles.

What is inside this post

Definition – Basepath, Baseline, Distance between bases

I have seen a lot of confusion about the basepath, baseline, and distance between bases. These words are loosely thrown around so please allow me to clarify them as they are not the same:

Distance vs Baseline vs Basebath
(click to enlarge)
  • Baseline is the actual running distance measurement between bases (sometimes referred to as bags or stations). Baseline for home-to-first, and third-to-home are the same as right field and left field foul lines, respectively. Baseline for first-to-second, and second-to-third base are invisible
  • Base path (or “basepath”) is created by the base runner “when the tag attempt occurs” -MLB Rule 5.09(b)(1)
  • Distance between bases is the physical measurement between bases. For MLB ballparks, the established measurement is 90 feet.

Impact of Larger Bases in 2023

In summer of 2022, Major League Baseball announced that it is increasing the size of its bases from 15 inches to 18 inches for the 2023 season (Minor League made the switch for the 2022 season).

Base Size Change – 15 inch to 18 inch
  • OLD Base
    • Dimensions: 15 inches by 15 inches (38.1 cm x 38.1 cm)
    • Area: 225 square inches (1451.61 square cm)
    • Height: 3 to 5 inches (7.62 cm to 12.7 cm)
  • New Base
    • 18 inches by 18 inches (45.72 cm x 45.72 cm)
    • Area: 324 square inches (2090.32 square cm)
    • Height: 3 to 5 inches (7.62 cm to 12.7 cm)
This increase by 16% in length and 30% in total coverage area reduces the baseline distance by three inches but the overall measurement between bases remain the same at 90 feet.

How does this size change younger baseball leagues

Except for NCAA college baseball, base size change is not expected to impact youth leagues:

  • American Amateur Baseball Congress (AABC): There is no plan change to larger bases
  • American Legion: Most American Legion balls are played on high school fields so the base size will remain at 15″
  • Babe Ruth/Cal Ripken: No changes for 2023 on base sizes but it will revisited by the rules committee at its annual meeting in August 2023
  • Continental Amateur Baseball Association (CABA): No rule changes for 2023
  • Dixie Youth Baseball: The base size will be revised at its national meetings in August 2023
  • Little League Baseball: No changes for 2023
  • NCAA: The NCAA Baseball Rules Committee will permit larger bases in non-institutionally owned facilities, which eliminates the need for a waiver for colleges to play a game in a Minor League or MLB stadium. This decision will be revisited in 2024.
  • NFHS: No changes are currently anticipated at the high school level regarding the size of the bases from the National Federation of State High School Associations (NHFS). 
  • PONY Baseball: PONY Rule 7H has been changed to “bases shall not be smaller than a 15-inch square” which gives local leagues the option of continuing to use present-sized bases or switching to the larger MLB-sized bases
  • USSSA: No changes for 2023
Why are the bases closer together for youth baseball?

Youth ball players are physically smaller and shorter.  Since the distances between bases have direct implications on the gameplay and player development, influencing aspects like base running speed, hitting strategy, defensive positioning, and skill progression among younger players, they play on smaller fields.

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Changing Times and Changing Sizes

There are thousands of ballparks across America, ranging from sandlots, to well-worn town baseball fields, to the MLB stadiums.

The origin of baseball fields dates back to the mid-19th century, and their design has evolved over the years when Knickerbocker Club of New York formalized the initial rules of baseball, with the bases as a key component back in 1845.

Baseball Base made of burlap (1800s)

These rules, however, did not define a specific distance between bases. Instead, they stipulated that bases should be from “42 paces” (about 126 feet) to “stools placed opposite each other at the distance of 42 paces apart”.

In the late 1850s, the baseball pioneers were beginning to find that a standard field size created a more balanced and competitive game. During a convention of baseball clubs in 1857, it was proposed to standardize the distance between bases at 90 feet, which was adopted by the National Association of Base Ball Players (NABP) in 1859. This distance was slightly shorter than the average baseline in use at the time, but it was deemed to provide the best balance between offensive and defensive play.

The origin of the 90 feet distance is not definitively recorded, but there is a popular myth that attributes it to a simple practicality: the person who laid out the original baseball diamond (likely Doc Adams, a member of the Knickerbockers) simply paced out a square of 30 steps (90 feet) per side.

These distances became fully standardized when professional baseball was established. The professional National League, established in 1876, adopted the New York game’s diamond and field layout, with bases 90 feet apart, which is still the standard for professional baseball today.

1869 Rule (replica by author; click to enlarge)

Below is a summary highlight of dates and events associated with the creation of the baseball and the evolution of its field dimensions:

  • 1845: The New York Knickerbocker Base Ball Club, considered one of the first organized baseball teams, developed the Knickerbocker Rules. These guidelines established the layout of the field with a diamond-shaped infield, but the base distance was not specified
  • 1854: The first recorded baseball game played using the Knickerbocker Rules occurred
  • 1857: The Knickerbockers and 15 other New York area clubs formed the National Association of Base Ball Players (NABBP). During their convention, they proposed standardizing the measurement between bases at 90 feet, but it wasn’t formalized until 1859
  • 1876: The establishment of the National League brought further standardization to baseball field dimensions. The pitcher’s distance was set at 50 feet from home plate to the pitcher’s plate (or “rubber”), but the mound did not yet exist
  • 1883: The size of home plate was standardized to its current 17-inch width
  • 1887: The pitcher’s rubber was moved back to 55.5 feet from home plate
  • 1893: The pitcher’s mound was moved to its current distance of 60 feet, 6 inches from home plate. This was in response to the high scoring games of the time, with the intention of restoring some balance between batters and pitchers
  • 1903: The foul lines were extended indefinitely, instead of stopping at the 1st and 3rd base
  • 1950s: Most Major League ballparks started to standardize the distance of the outfield fences, although there is still considerable variation today

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Home to First Base (or Home to Third Base)

The standard distance between bases, including from the home plate to first base (or home to third base) in Major League Baseball, NCAA baseball, and high school is 90 feet.

  • The distance measurement between the home plate to first or third base is taken from the back point of home plate to the back corner of a base.
  • The baseline measurement is taken from the back point of the home plate to the front corner of a base
  • Basepath measurement cannot be pre-determined since the “distance” is only created from the spot where the runner was at the time when a defender attempts to make a tag
Measurement from Home and First or Third Base

First Base to Second Base (and Second to Third Base)

Measurement from first to second base

There are two unique things about second base.

First, there is no “foul line” connecting first-to-second-base and second-to-third-base. Instead, they are “invisible”.

Second, the base itself is centered on these two invisible, bisecting baselines from first-to-second and third-to-second bases.

Because how the second base is aligned, measuring the distance between the first and second base (and second to third base) is slightly different.

Instead, the baseline is measured from the far corner of first base to the center of second base.

Home plate to Second Base

The standard distance from home plate to second base is 127 Feet, 3⅜ Inches.

Distance between home plate and second base

This distance is determined using the Pythagorean theorem based on the right triangle formed by the paths from home plate to first base, first base to second base, and second base back to home plate.

Using the same formula, we see that the same distance for 50/70 field is approximately 99 feet and 85 feet for 46/60.

As mentioned in the history section, remember that the second base is not inside the “diamond” so the distance end point is the center of the second base.

Second Base – alignment with baseline

The distance from home plate to second base is crucial since this is the first distance set to create the baseball diamond.

Third Base to First Base

Directly measured, the distance between third base and first base is approximately 127 feet, 3⅜ inches – the same as the distance from home plate to second base.

Pitching Mound to Home Plate

Distance between pitching mound and home plate

The standard distance from the pitching mound to home plate in Major League Baseball is 60 feet, 6 inches.

This measurement is taken from the rear point of home plate to the front edge of the pitcher’s rubber.

The National League first set the distance at 45 feet in 1876, but it was progressively moved back to its current distance by 1893 to counter the high number of runs being scored.

For youth leagues and some amateur leagues, the pitching distance is often less than 60 feet, 6 inches to account for the different physical capabilities of younger or less experienced players. For example, in Little League, the mound is just 46 feet from home plate.

Pitch Speed and Reaction Time and Distance in Pitching

The distance between the pitching mound and home plate impacts how much time a batter has to react to a pitch.

At the standard distance, a fastball traveling at 90 mph gets to the batter in about 0.44 seconds. Any change in this distance can significantly affect the balance between pitcher and batter.

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The precise measurements that define a baseball field, including the distance between bases and the distance from the pitcher’s mound to home plate, are fundamental to the strategies, dynamics, and fair play of the game.

The 90-foot distance between bases sets the stage for a range of strategic decisions and intense moments, while the 60 feet, 6 inches distance between the pitcher’s mound and home plate impacts the balance between the pitcher and batter, affects player health, and influences the game’s pace.

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