Baseball and Vision Series: Fielding

When discussing visual skills and baseball, most conversations focus (pun intended) on batting, which indeed is one of the most visually demanding tasks in professional sports.   Pitching also requires good visual skills, but fielding is also overlooked in discussions around vision and baseball performance.

Let’s break fielding down into 3 groups;  Infielding, Outfielding and Catcher Fielding, as these three different groups use different visual skills in many situations.  We will discuss infielding and outfielding in this post and save catching for a later time.

Infielders handle line drives, grounders, base-stealers and the occasional infield fly.

Line Drives:  The major league average velocity of a ball-off-the-bat is 104 mph.  With a projectile heading at your body at that speed, visual tracking, reaction time, acuity and depth perception play an important role in one’s ability to get a glove on it.  Visual tracking starts the second the ball leaves the bat.  The image of the trajectory of the ball as it leaves the bat is projected on the retina (the back of the infielders eye) is used by the brain to calculate (a) the approximate speed the ball is approaching and (b) the x, y, z coordinates that the ball is most likely to cross from the fielders “ready position”.  This enables the fielder to adjust position slightly and estimate what direction he might have to lunge to get to the ball; either forwards, backwards, up, down, right, left,  or a combination of these movements that might also happen directly in front of his body.

Visual cues are used to gauge reaction time in order to align glove with ball and capture the ball by closing the glove in a timely manner.

Visual acuity (clarity) is important, as blur causes the image of the ball that falls on the players retina to appear larger than it actually is, and this can throw off the other visual cues used to trap the ball in the glove.

In order to catch any ball, Depth perception needs to be intact for the brain to make the calculations with data provided by other visual cues accurately.  Depth perception happens when the eyes are able to fuse the image from each eye in the brain, and the eyes also use what are called “depth cues” to judge depth as well.  If a player doesn’t have good depth perception, he may rely on depth cues to judge the ball, however he will never be able to field the ball as well as a player who has good depth perception.  Depth cues include perspective, shading, occlusion, haze, and relative motion.  If depth cues are eliminated, all the depth perception in the world won’t help someone field a ball – for instance, it might be impossible to judge a line drive if it is foggy out, or if the color of the ball didn’t provide good image contrast against the background the fielder had to discern the ball from, such as the crowd or the grass.

Infielders also need to be able to use these cues to trap grounders; reaction time is key to catching

Infielders also rely heavily on peripheral vision and reaction time as they are responsible for keeping base runners from stealing.

Outfielders usually are responsible for handling fly balls, and as such are required to have excellent depth perception and be able to interpret depth cues. They also must have good tracking skills, but they have longer to assess the trajectory of the ball and get their body in the correct position to catch the ball.

Peripheral vision comes into play when two fielders are chasing after the same ball – they must be aware of each others position to avoid colliding both in the interest of saving a base or a run and in the interest of saving themselves from the trauma.  Baseball players are taught to yell “mine” or “I got it” so they don’t have to count on their peripheral vision to avoid these collisions.

Tracking becomes more important for fielders when they attempt to save a ball from becoming a home run – they use their peripheral vision to estimate their distance from the wall, they use tracking to estimate when and where to launch themselves and how to position their glove to increase their odds of catching the ball, and, of course, timing to make the catch (or miss it for that matter!)

Courtesy of the Doctors at Shady Grove Eye and Vision Care; Optometrists, Ophthalmologists and Opticians working together to help you see better.  Serving the Rockville, Potomac and Gaithersburg Maryland suburbs of Washington, DC for over 40 years. For more information visit or call (301) 670-1212

Connect with us on Twitter @EyeInfo


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