Are Umpires Playing Favorites? Baseball Strike Zone Defined 

John Means

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Baseball Strike Zone Defined 

Have you ever been to the dugout in a baseball? Or, had a grandstand near the coach’s box? If yes, then you must have heard the term “Baseball Strike Zone”

Not ringing a bell? You are a die-hard baseball fan and haven’t faced a situation where players complain about the umpire’s strike zone, can’t be possible!  

The strike zone is one of the most essential fundamentals of baseball. It grabs the hottest arguments too! 

Thus! It will be unfair for us not to cover an article on Strike Zone. Today, we get into the detailed components of the Baseball Strike Zone. 

What is Baseball Strike Zone? 

According to MLB Rules 2 – Section 35, a strike is a legal pitch when declared by the umpire. The rule also defines, 

The strike zone is that space over home plate, the top of which is halfway between the batter’s shoulders and the waistline, and the bottom being the knees, when he assumes his natural batting stance. The height of the strike zone is determined by the batter’s normal batting stance. If he crouches or leans over to make the shoulder line lower, the umpire determines height by what would be the batter’s normal stance.

Find it hard? We are going to make things simpler for you. 

You may get the wrong idea about the strike zone at first glance. We are not talking about a two-dimensional area here. The strike zone is a three-dimensional area in baseball. 

It has both – width and length and reflects the shape of the home plate. In baseball, a strike zone is already set at the moment the hitter initiates the swing motion to hit the baseball.

While different leagues define the boundaries differently for the strike zone. One thing is certain! The strike zone in different organizations come with the same length and width; with the same purpose. 

Dimension of the Strike Zone

The width of the strike zone is always the same regardless of the leagues and fields. It is 17 inches (43.2 cm) and it will always remain 17 inches. It has 8.5 inches on both sides and the middle of the plate is 0 inches. 

And the height of the strike zone is a measurement, unlike a fixed number. 

It is usually determined by the in-between space from the bottom of the hitter’s knee to the middle point between the hitter’s shoulder and the top of the batter’s pants. Don’t get lost in wordplay! 

To put it simply, the height of the strike zone often depends on the height of the hitter. Additionally, how the hitter prepares to swing the ball. 

The height of the strike zone is usually between 1.5 feet to 3.6 feet from the ground; given that the batter is using the pitchRx package through RStudio and his height is not a factor. 

Keep A Few Things in Mind:

pitchRX package: is an information hub with all the Major League Baseball Advanced Media’s ‘Gameday’ data. It provides an easy yet powerful method to generate strike-zone plots using the ‘ggplot2’ package. It includes PITCHf/x data. 

Pitchf/x data is from the Catcher/Umpire perspective. It offers a negative horizontal location to the left and a positive to the right.

RStudio: In baseball, RStudio is a convenient interface. It comes with a built-in data viewer to preview all the essential stats of the game in a window. 

It might become a hassle to determine the height of the strike zone. Because information disclosed publicly doesn’t include the hitter’s handedness or pitcher’s name. Due to this, we will have to work with a motionless strike zone for now. 

What Does A Strike Ball Mean in Baseball? 

Baseball Strike Zone Defined 

The strike zone determines whether the pitch is called a strike or a ball. It has changed over the years to establish a balance between offense and defense while making room for changes in the size and style of players.

In baseball, a ball is struck when any part of the ball gets in contact with any part of the home plate. In other words, the ball has to pass through the strike zone. This is as simple as we can explain to you.
But inside the umpire’s head, there’s always this calculation. Before passing down a fair judgment, they have to think of an imaginary line in their head. This line is vertical and comes from each boundary of the home plate. 

Two scenarios are the possible outcome of this: 

  1. The Ball is Strike: In case the pitch crosses the imaginary vertical line within the right height, the pitch is a strike.
  2. It’s a Ball: The ball may fall outside the imaginary line or it may not have the right height, in this case, the pitch is a ball. 

Other scenarios, you may not be aware of are: when a hitter has less than two strikes, a foul ball will also count as a strike and the hitter will be out. Plus, when a batter has three strikes, he is also out. 

Keep in mind that, part of the baseball must cross over the part of the home plate within the strike zone. Not always a strike will result in an out and that’s what we have to take note of. 

Factors the Umpires Should be Concerned about? 

To pass an instant decision on the ball being a strike, the umpire has to make calculations in his head. He only has a few seconds to deliver his decision. 

Since the batter’s approach in batting is a crucial factor to determine the strike, umpires have to tactically deal with the batter’s speed. The pitchers throw at a fast speed. Usually, they target 90 mph for the fastballs (as recorded in Major League Baseball). What can go wrong here?
Thus, allowing the umpires only a few times to figure out whether the ball is inside the strike zone or outside the strike zone. So, when does the umpire start? 

His moment of judgment begins right from the moment when the batter starts to swing.  Plus, he also has to determine the height of the strike zone based on the height of different players. 

Different players have different heights. This is why, the height of the strike zone will also vary from hitter to hitter.
Phew! Keeping note of the batter’s approach, physical features, and speed at the same time is not as easy as it might seem.

How Does Height Affect Strike Zone? 

Yes, of course, the height is one of the crucial parameters of the strike zone. The strike zone is different for different players. We can say, it is an individual characteristic linked to batters in baseball. 

The height of the strike zone varies based on the specific body part of the batter. For example, you will have a bigger strike zone for a taller batter and the size will go down for a shorter player.

You should also consider their body posture. It is so common for the batters to crouch while they are in their batting posture. While most batters crouch a little while they initiate the pitch, others may crouch a bit further.
However, crouching can effectively influence the strike zone. For example, you will have a shorter strike zone with a tall player who crouches more than a shorter player who crouches a little. 

A possible reason behind this can be explained here. While a batter crouch, the upper part of his body is closer to his knees; thus reducing the zone of strike even a little. 

However, the strike zone is not often left on the batters. Different baseball leagues and organizations including Major League Baseball determines strike zone differently.
In Major League Baseball, the Strike zone is determined when the batter is ready to swing. While others define strike zone differently. 

However, some baseball leagues prohibit crouching saying, no batter should attempt to shorten the strike zone by crouching longer. This may affect the baller. We think it’s justice for the baller. 

Do Umpires Always Do It Right? 

Before we start, let’s be honest – the strike zone doesn’t exist in reality. Umpires have to get the idea of a strike zone in their head.
Imagine being in the field and drawing a virtual space in your head to calculate the possibility of a strike! It may seem easy but can often result in an error. And, that’s okay! 

Umpires are human and to err is human. 

Baseball officials often crack a joke on serious decision making, “Every time we make a close call, we earn a temporary friend and a permanent enemy.”

Well, it’s true! While an umpire calls for a strike, the manager of the opposing team sitting in the dugout may speak out for a challenge. Although, it is advised to not bear any hard feelings in mind and what happens in the field, stays in the field. This may not back you up always. 

Stats show that umpires call 99.5% of calls correctly while the rest of the 0.5% may not be helpful in relationship building. 

However, data from Boston University says something otherwise. Based on their report, Major League Baseball umpires missed 34,294 Ball-Strike Calls in 2018. That is 14 wrong calls per game; assuming that the number of incorrect calls covers at least 20% of their time in baseball. 

Thus, you can get that, umpires are not always right. There is no need to worry. If they get the call wrong, managers can come forward and request a challenge to review replays. Recently, MLB implemented new replay rules after spring training. Give it a read

Average Size of The Strike Zone? 

Now that we are here, you must be wondering, in the previous section, we have already learned about the size of the baseball strike zone. What’s the stoppage here?
Since Strike Zone varies from batter to batter. Plus, different leagues can enforce different methods to determine their strike zone. Hence, you better know the average size of a strike zone.   

Let’s assume the batter’s height is 5.8. This batter will create a strike zone of 28 inches in height. We already discussed the width of the strike zone remains the same since it is also the width of the plate. Thus, the width of the strike zone will be 17 inches always.  

Batters Could Tell Their Own Strike Zone

Can you believe that? Back in 1876, baseball batters could select their strike zone. They could inform the umpire whether they wanted the ball high, low, or medium. The pitchers would pitch following the batter’s strike zone. The batters would want to: 

High Pitch: For a batter, the high strike zone was between the batter’s shoulders and waist.

Fair Pitch: The fair strike zone was between shoulders. And the height would be at least one foot from the ground. 

Low Pitch: A pitcher had to avoid between the batter’s waist and keep it at least one foot top from the ground.
During this time, batters had liberty but not for too long. While batters had their personal preference to select their strike zone, this created chaos among the pitchers. Pitchers thought this offered some unfair advantage to the batters. Thus, they often argued with the umpires to get things right. 

Final Words 

The baseball strike zone was only subjective during the early days of Baseball. However, as time passed, the need to idealize the strike zone became clear. 

Recently, discussions took place to effectively modernize the strike zone using technology, such as automated strike zones. This would remove the concept of imagination and ensure a consistent strike zone across all games. 

However, automated strike zones would require careful consideration and potential adjustments to accommodate different batter heights and stances.

So, what do you think? Do you think the traditional method of figuring out the strike zone is okay or the system needs some modern feature to help the umpires? Leave a comment below and let us know.
You can also share this article with your baseball friends to help them have a deep understanding of the strike zone. 

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John Means

John Means is a professional baseball player who has played in the major leagues for the Kansas City Royals and the Oakland Athletics. He made his major league debut with the Royals in 2009. He was traded to the Athletics in 2012. Baseball is his favorite sport. His passion about the game is evident in his play. Now he write blogs about baseball and other things whenever he has some free time. LinkedIn

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