Are Baseball Players Superior to Umpires in Discriminating Balls to Strikes?

This article was written by Christoph Kreinbucher

This article was published in Spring 2012 Baseball Research Journal

Missed, bad or wrong calls are part of nearly every game and can have an influence on the run of the play as well as the final score. Emotions can run particularly high when a player perceives a pitched ball is out of the strike zone but the umpire calls “strike.” Is it possible that a batter is better at judging whether a ball is in the strike zone than an umpire? If so, what can this be attributed to?

Missed, bad or wrong calls are part of nearly every game and can have an influence on the run of the play as well as the final score. Emotions can run particularly high when a player perceives a pitched ball is out of the strike zone but the umpire calls “strike.” Is it possible that a batter is better at judging whether a ball is in the strike zone than an umpire? If so, what can this be attributed to?INTRODUCTION

When umpires allegedly make a wrong call, they open themselves to criticism from players, coaches, spectators, or even newspapers.[fn]Tyler Kepner , At first, fireworks over the umpiring, The New York Times, October 23, 2011, Retrieved from[/fn] Missed, bad or wrong calls are part of nearly every game and can have an influence on the run of the play as well as the final score. Recall the 2005 American League Championship Series between the Chicago White Sox and the Los Angeles Angels of Anaheim when a controversial call in the ninth inning led to the difference in the game. Chicago had recorded two outs in the inning and their batter already had two strikes. He then missed strike three, but was allowed to take first base after the third strike bounced out of the catcher’s glove (the catcher thought the same as a majority of the Angels players, that the inning was over). By advancing to first on the dropped third strike, the batter extended the inning and changed the outcome of the game.

The given example shows the importance of calls at home plate and what they can lead to. Emotions can run particularly high when a player perceives a pitched ball is out of the strike zone but the umpire calls “strike.” Is it possible that a batter is better at judging whether a ball is in the strike zone than an umpire? If so, what can this be attributed to? 

“Ball” and “strike” calls constitute a unique sports judging situation that can be found only in baseball or softball. The strike zone is virtual and not determined by clearly visible boundaries like in other sports such as tennis (“in”/“out”) or soccer (“goal”/“no goal”) in which fixed lines are indicated on the playing surfaces or defined by poles or other physical features. Accordingly, determining the specific moment in time when the ball is exactly above home plate is difficult. Moreover, it is problematic to estimate this point in time from behind; where the umpire positions himself could make calling balls and strikes more difficult. This was the main topic of an investigation in which the authors compared the traditional position of the home plate umpire with four alternative perspectives.[fn]Ford, G.G, Gallagher, S.H. & Lacy, B.A. (1999). Repositioning the home plate umpire to provide enhanced perceptual cues and more accurate ball-strike judgments. Journal of Sport Behavior, 22, 28–44.[/fn] The results revealed that a position behind the outside corner, farther away from the batter, led to more accurate calls. The advantage of that particular position are two-fold: one, additional height and distance cues, and two, the advantage of being able to see pitches pass in front of the batter. Umpires ought to be aware of this problem and should position themselves as advantageously as possible in order to increase the likelihood of making more accurate calls. 

Another reason the ball/strike decision is unique is because the home plate umpire and the batter are positioned closer together than can be found in any other sport. One can say that they view pitches from nearly the same vantage point. In one of the first scientific investigations on officiating in baseball, the umpire’s knowledge of the official rules was compared to that of the players.[fn]Rainey, D.W. & Larsen, J.D. (1988). Balls, strikes, and norms: Rule violations and normative rules among baseball umpires. Journal of Sport and Exercise Psychology, 10, 75–80.[/fn] While umpires were more knowledgeable about the official rules than players, there was a different perception of the strike zone. Umpires admitted that they called the upper boundary of the strike zone significantly lower than the official rule specified. This is thought to be to the advantage of the batter, but still an error according to the rules. Further, a related study demonstrated that umpires sometimes adopt different criteria for calling borderline pitches balls or strikes depending on the pitchers’ reputation.[fn]Rainey, D.W., Larsen, J.D. & Stephenson, A. (1989). The effect of a pitcher’s reputation on umpires’ calls of ball and strikes. International Journal of Sport Behavior, 12, 139–150.[/fn] When participants were told that a pitcher has little control of his throws, the strike zone was enlarged and a borderline pitch was more often called a strike in comparison to a control pitcher, where the strike zone was narrowed and a borderline pitch was called a ball. Another investigation showed that umpires can be biased in their calls depending on the sequence of balls and strikes.[fn]Paull, G. & Glencross, D. (1997). Expert perception and decision making in baseball. International Journal of Sport Psychology, 28, 35–56.[/fn] These investigations demonstrate that certain factors can bias umpires in their decision-making process and lead to wrong calls. 

For proper discrimination of balls and strikes, perceptual experience is important. Several studies in fast ball sports showed that experts have superior anticipation skills when compared to less skilled counterparts and novices.[fn]Abernethy, B. & Zawi, K. (2008). Pick-up essential kinematics underpins expert perception of movement patterns. Journal of Motor Behavior, 39, 353–367.[/fn],[fn]Van der Kamp, J., Rivas, F., van Doorn, H. & Savelsbergh, G.J.P. (2008). Ventral and dorsal contributions in visual anticipation in fast ball sports. International Journal of Sport Psychology, 39, 100–130.[/fn] A common explanation for this is that experts have been more exposed to the corresponding sport-specific situations and as a result they are 

perceptually better attuned to the task-relevant information. One can therefore conclude that professional players and umpires share perceptual experience gained through watching many pitches in their careers. The fact that they have two different tasks to execute makes the whole situation even more interesting. While umpires “only” have to give a verbal judgment as to whether the pitched ball was in or outside the strike zone, a batter has to not only make the same determination, but also to transfer that judgment into a swing, to hit the ball at the proper time. The difference in those tasks could have an influence on the decision-making process of umpires and players and therefore their abilities to discern balls from strikes. Two previous scientific investigations have addressed this issue.


In an investigation conducted in Canada, umpires, players, and control participants without any relevant baseball experience were compared on their ability to make ball and strike calls.[fn]MacMahon, C. & Starkes, J.L. (2008). Contextual influences on baseball ball-strike decisions in umpires, players and controls. Journal of Sport Sciences, 26, 751–760.[/fn] Video clips in which several pitches were filmed from the umpire’s point of view were used as testing material. To emulate a game scenario the camera was mounted on the head of the umpire, who was asked to minimize his movements as much as possible. The researchers then recorded pitches from a left- and a right-handed pitcher. They asked the two pitchers to throw balls and strikes with varied pitches, such as fastball and slider. The starting point of each video clip was when the pitcher took the set position on the mound. Three experienced umpires judged the clips independently to determine the criteria ball or strike. In the end, 38 ball and 23 strike pitches were used. The results revealed that both umpires and players scored higher accuracies than the group of novices, whereas players scored the highest accuracy but without any significant differences between them and the umpires.

A further step was taken in an investigation in the Netherlands with a similar design but a different approach.[fn]Kreinbucher, C., Cañal-Bruland, R. & Oudejans, R.R.D (2010). Der Einfluss motorischer Expertise auf die Beurteilung von “Ball” und “Strike” im Baseball. [Motor experience influences strike and ball judgments in baseball.]. In G. Amesberger, T. Finkenzeller & S. Würth (Eds.). Psychophysiologie im Sport – zwischen Experiment und Handlungsoptimierung (149). Hamburg: Czwalina.[/fn] They also used three different groups at three different levels of expertise (skilled baseball players, experienced baseball umpires, and novices) in the experiment. The basic idea of this experiment was to get an insight into the decision-making process of players and umpires by using both of their game-specific tasks in an experiment in a lab. Although both umpires and players are attempting to judge whether a pitch is a strike or a ball in a game situation, the umpire’s game-specific task is to announce verbally (or by use of hand signals) whether the pitch is a strike or ball, and the batter’s game-specific task is to decide whether to swing the bat or not. 

All three groups were asked to judge some pitches by simply saying “ball” or “strike,” but a second task was also added. For other pitches, participants were given a real baseball bat, which they were instructed to swing when they considered to be the proper time to “hit” the ball if they thought the ball was inside of the strike zone. Participants were also instructed to stand still or stop the swing if they thought the ball was going to be outside of the strike zone. As testing material, two sets of 60 video clips were presented on a life-size screen. In contrast to the investigation of the Canadian researchers, this experiment showed a difference in the accuracy of players and umpires in the ability to discern balls from strikes. In total, players’ ball and strike calls were much more accurate than umpires or novices, and no difference between the umpires and novices was found. Players were also more correct in discriminating balls from strikes than umpires, irrespective of the experimental condition, whether giving a verbal response or a motor response. It seems to be that players outperformed umpires not only in their accustomed game-specific task using the baseball bat, but also in the verbal task which is what umpires are used to doing in a real game situation. The authors argue that the superior performance of players seems to be related to the motor experience  they gained while swinging their bat in many games throughout their career. This is an interesting finding which could lead to some speculations about how to improve the training of umpires. [Editor’s Note: We hope to present the full findings and details of this study in a future issue of the Baseball Research Journal.]

Although there are differences in the accuracy scores between players, umpires, and novices, the results from the presented investigation are limited to a certain extent. Due to the artificial situation in a laboratory one could argue that this is a completely new task for everyone. The advantage to using a controlled setting is that other influences such as the ones found in the earlier mentioned investigations can be eliminated.[fn]Rainey op. cit., Paull & Glencross, op. cit.[/fn] Still, there is a difference between having to judge a ball moving in three-dimensional space in a real-game situation than judging video clips on a two-dimensional screen. 


Although the mentioned studies are mostly preliminary and further research has to been done to address which factors are responsible for differences in the accuracy between the groups in calling balls and strikes, possible practical implications should be discussed. If we follow the interpretation of the researchers that a baseball player’s motor experience in performing a bat swing could help them to perceive the difference between balls and strikes, one could ask if umpires could improve their pitch-calling abilities if they gained the same motor experience of swinging a baseball bat at home plate. A similar question was asked by German researchers in relation to soccer.[fn]Pizzera, A. (2010). Verbessert “Schwalbentraining” das Erkennen von Schwalben? [Does special “dive training” improve the recognition of dives]. In G. Amesberger, T. Finkenzeller & S. Würth (Eds.). Psychophysiologie im Sport – zwischen Experiment und Handlungsoptimierung, 149. Hamburg: Czwalina.[/fn]

Their research highlighted the difficulty of judging whether a foul should lead to a penalty kick or not. Nowadays, it is common for players to use theatrical abilities to fall down spectacularly when (almost) touched by an opponent in the penalty area in order to have a penalty called. For a referee, it is difficult to judge whether a foul was genuine or just a “dive.” The concept behind this investigation was that referees had to learn to fall like players in different training sessions (i.e. gain motor experience in performing this task) so they could better estimate the ambiguous tackling situation. The results revealed that referees who participated in the training sessions were more often correct in their later decisions concerning whether a situation shown via a video clip was a real foul or if the player pretended to be fouled. Similar training sessions could easily be conducted in baseball.

Independent of the differences between players and umpires, the investigation showed that wrong calls are common and cannot be avoided. In this respect the discussion of the usage of technological devices should be advanced. Since 2008, Major League Baseball allows instant replays, but only for boundary calls associated with home runs. Instant replay is used in sports such as ice hockey and tennis. In tennis, umpire decisions can be challenged with the help of a “hawk-eye” system three times in each set, with one additional challenge if a set is decided in a tie-break. Although the equipment and the possibilities exist, baseball is not using the technological potential. The question is one of what is wanted in this sport. Is there a wish for a complete technological observation, which will provide absolute clarity about the calls, yet also cause a possible delay in the game? Or, is it desirable to have the fruitful debates between fans, commentators, and the press? These animated discussions, heated arguments, and passionate face-offs are a major factor which keeps spectators interested in the sport. 

The fact is, we should not forget that to err is human. If we are to follow that adage, then we should treat umpires and referees with respect and not only honor their work, but facilitate their attempts to improve the accuracy with which they are making decisions. We can do this by ensuring that further research is conducted directly on the baseball field to create and observe situations as close to reality as possible. Therefore, new technological improvements should also be included as long they do not affect the game in its general cycle. Furthermore, technologies such as the PITCHf/x system should be used for the purpose of training umpires. The advantage of such training could be that immediately after the decision of an umpire, feedback can be given whether the ball or strike call was right or wrong. Umpires could therefore adapt their judgments with a cognitive reevaluation of their reference lines. The success of direct feedback after a judgment for umpires and referees has been shown in training studies in tennis and soccer.[fn]Jendrusch, G. (2002). Probleme bei der Bewegungsbeobachtung und – beurteilung durch Kampf-, Schieds- und Linienrichter. [Judges’, referees’, and linesmen’s difficulties in the perception and evaluation of movements]. Psychologie und Sport, 9, 133–144.[/fn], [fn]Schweizer, G., Plessner, H., Kahlert, D. & Brand, R. (2011). A video-based training method for improving soccer referees’ intuitive decision making skills. Journal of Applied Sport Psychology, 23, 429–442.[/fn]

Ultimately, umpires must be given the skills to succeed at their task. This study and the other research cited suggest that increased motor experience (swinging the bat) and training sessions involving PITCHf/x feedback on ball and strike calls would most likely improve umpires’ abilities to judge the strike zone. 

In an effort to close the discussion on the use of technology in baseball with regards to umpire training, consider the insightful summary as offered by The New York Times: “A mistake by a player cannot be reversed by technology. A mistake by an umpire can, if baseball would allow it.”[fn]Kepner, op. cit.[/fn]

CHRISTOPH KREINBUCHER is a sport psychologist currently working at the Technische Universität in Munich, Germany. He studied psychology in Graz, Austria and spent some time in Amsterdam, Netherlands where he conducted the experiment presented in this journal. In his Ph.D. thesis, he specializes on neuronal correlates of judgment and decision making. Next to his research work, he works as both a sport psychological consultant with athletes from various sports and as a professional tennis umpire.