How Accurate Is The Baseball Strike Zone Box On TV

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Every baseball game on TV now has one of those strike zone boxes, which tell us if the ball was over the plate or not. However, we have all disagreed with what those systems tell us. Sometimes several times a game.

Does that mean we are wrong? Not necessarily. It turns out that for various reasons, these boxes can be wrong.

What is the Strike Zone?

The strike zone is the area within which a pitcher must throw the ball, for the pitch to be called a strike if the batter does not attempt a full swing. In spatial terms, it is the zone directly above Homeplate and between the batter’s knees and the exact midpoint of the torso.

This means, that the strike zone can change dramatically from batter to batter. If the ball touches any part of the strike zone while going over the plate, it is within the strike zone. Only a ball missing the zone altogether will be called a ball if the batter does not swing at it.

Why Does it Matter?

The strike zone is a crucial element of the game. The wider the zone, the easier it is for a pitcher to strike the hitter out. The smaller the zone, the easier for the batter to predict where the ball goes and hit it solidly.

Major League Baseball has at times adjusted the zone as a means of balancing offense and defense in the game. In the 1950s and early 1960s, there was a crazy home run explosion. Guys like Mickey Mantle, Hank Aaron, Willie Mays, and Roger Marris hit over 40 home runs regularly.

When Marris broke the record in 1961, the top brass decided enough was enough. The strike zone was expanded, giving pitchers a tremendous advantage.

By the late 1960s game had the opposite problem. Pitchers like Bob Gibson and Juan Marichal were posting impossibly low ERA’s. Meanwhile, batting averages and home run hauls plummeted. So the strike zone was expanded again.

There is no doubt that the strike zone is a VERY important part of the balance of the game. But how accurate is it? For generations, umpires made the call on their own.

It was a very subjective process and some umpires were known for their expansive interpretation of the strike zone. Others were known for being very stingy with strikes. Arguing with the umpires, and cursing them mightily, became an integral part of the game. This became such a problem, that today if an official gets off the bench more than once to object to a call, they are to be ejected from the game.

Electronic Strike Zone Identification Systems

In the 1990s, the MLB introduced the first electronic device for tracking pitches to help umpires make calls. The machines provided by QuesTec systems were quite advanced for their time.

However, they drove pitchers crazy. Many felt that it had narrowed the strike zone unfairly, forcing pitchers to change their styles. Phillies ace Curt Schilling once destroyed a QuesTec system camera out of frustration.

The systems have become significantly more accurate since. In 2009, the Zone Evaluation system was introduced. It tracks the ball in twenty different positions on its way to and at the plate, to determine whether the pitch was a strike or not.

The Strike Zone on TV

Television broadcasters have been using technology to track pitches for decades now. The first system was introduced by NBC in 1983, showing the entirety of the path from the mound to the plate. It was only in 1997 however, that the first graphics of pitch position concerning the strike zone began to appear regularly on broadcasts.

Now every major broadcaster has that box in the picture. Many fans consider them a distraction from the actual game. Are they worth the investment and distraction? How accurate are these systems?

Major broadcasters claim that their projections are correct to within one inch of actual ball position. However, there are reasons to question this claim. All machines are inaccurate to some extent.

To calibrate the accuracy of one mechanical system, another machine is used. And guess what? That machine is inaccurate too. To calibrate it… You get the picture.

Unfortunately, the producers of these systems do not provide information on the accuracy deviation of their products. They will all admit that their systems do not accurately process all of the data received on every pitch. It remains unclear if that is a minor issue or a more major one, due to a lack of transparency.

There are reasons for concern. Radio interference may alter the results in a meaningful sense. Even light rain can cause serious warps, even with the best procession available. Finally, some research has shown that the ability of these systems to fully compensate for the size of different batters is problematic for systems to process adequately.

The movement of the batter’s body significantly throws off the sensors, Remember, the rule book is very clear that the strike zone should be measured from the batter’s stance as he prepares to take that specific pitch. Therefore, an operator is normally used to do so for each batter. This opens the issue up to human error.

Another problem is the performance of the system in tracking the trajectory of complex pitches. The kind of sliders and low-spin pitches MLB hurlers throw out can alter speed and projection in a manner in which electronic systems have difficulty following.

The problems could stem from either the hardware or software of systems such as Statcast, used by many broadcasters. Every form of software suffers from bugs and other problems which may lead to inaccuracies.

Software is also vulnerable to hacking. It would not be particularly difficult to adjust the parameters to help one team over another. There have been no known cases of this occurring. Yet.

We would like to think teams would not take advantage of this vulnerability. However, a large amount of money is put into sports betting every year. The betting world does not necessarily attract the most scrupulous characters.

If you were betting large amounts of money on the game, wouldn’t you be tempted to tip the scales in your favor? I sure would be. Though the box on TV is not as appealing a target, it is also open to manipulation.

The answer to the question of the reliability of the software is in a very real way unknown. Manufacturers will not release all the relevant details. The best efforts of the relevant tech companies to find flaws in the system will only be partially successful.

When companies say they detect a 1-inch error rate on their calls, they are likely giving the best spin on their findings. This means, if they are getting different results from varying methods of calibration, they will use the more flattering figures. This is natural.

However, they may not be aware of the various measurement problems in their systems. After all, if aware: they would fix the issue or at least try. Therefore, it would not be surprising if the inaccuracy is closer to 2 or even 3 inches.

Computers may not be just human, but they are programmed by them. If the box on screen disagrees with your judgment, you may be right!