See the ball, hit the ball.

For those baseball hitters who can do the former, the latter comes much easier. Seeing, identifying and selecting which pitch to swing at is a combination of visual perception, brain processing and motor skill execution. Sure, the physics of hitting a baseball, measured by things called launch angle and exit velocity, determine the trajectory and distance of a batted ball. But it’s that pre-contact decision making process that gets hitters on base so they can score runs and win games. Just as bat speed, leg drive and arm strength define the distance of a hit, the purely cognitive skills of perception, information processing and hand-eye coordination pick out the best pitch to hit and, more importantly, which pitch to avoid.

And when you’re 5 feet, 9 inches tall, you rely on those brain skills much more than physical dominance to stay up in the big leagues. That’s exactly what Mookie Betts, right fielder for the 2018 World Champion Boston Red Sox, has done over his young four-season career. Sure, he won the AL batting title this year with a .346 batting average, but he also had a league high slugging percentage, with 32 home runs and 80 RBIs.

Substituting brain for brawn, Betts excels in a category of baseball analytics known as plate discipline, in other words, picking the right pitch to swing at and then making contact with that swing. In the pre-swing decision-making process, hitters with good plate discipline swing at pitches in the strike zone, not out of it. When they do decide to swing, they make contact more often with better hand-eye coordination.

These skills are evident when we look at three additional batting metrics; outside the zone swing percentage, inside the zone contact percentage and walk/strikeout ratio. In 2018, Betts only swung at 1 out of 5 pitches outside the strike zone (4th best in MLB) while he made contact with pitches in the strike zone 93% of the time he swung at them. This combination resulted in a walks to strikeout ratio of 0.89, which was 11th best in all of MLB.

But why? Why are some players able to process the visual stimuli of an approaching ball so much better than others? Why are some able to swing a round bat at a round object and make contact more often? Recently, two teams of researchers tried to discover a link between superior perceptual-cognitive ability and hitting performance. If found, this connection may offer an opportunity to identify the superstars of tomorrow based on their raw hand-eye coordination.

At the 2018 MIT Sloan Sports Analytics Conference, Kyle Burris and Greg Applebaum of Duke University presented their findings after reviewing the test results of 252 professional baseball players on a Nike Sensory Station, (now owned by Senaptec), a collection of nine computerized, sensorimotor assessment tasks:

The Visual Clarity task measures visual acuity for fine details at a distance.
The Contrast Sensitivity task measures the minimum resolvable difference in contrast at a distance.
The Depth Perception task measures how quickly and accurately participants are able to detect differences in depth at a distance using liquid crystal glasses.
The Near-Far Quickness task measures the number of near and far targets that can be correctly reported in 30 seconds.
The Target Capture task measures the speed at which participants can shift attention and recognize peripheral targets.
The Perception Span task measures the ability to remember and recreate visual patterns.
The Eye Hand Coordination task measures the speed at which participants can make visually-guided hand responses to rapidly changing targets.
The Go/No-Go task measures the ability to execute and inhibit visually guided hand responses in the presence of “go” and “no-go” stimuli.
The Reaction Time task measures how quickly participants react and respond to a simple visual stimulus.

Next, the research team compared these results to the players’ batting statistics (on-base percentage (OBP), walk rate (BB%), strikeout rate (K%), and slugging-percentage (SLG) ) for the following season looking for statistically significant correlations.

By far, the Perception Span task had the highest predictive power to better batting performance, especially in OBP and K% but also in BB% and SLG. This test presents a circular pattern of multiple dots, some turned on, some turned off. The user is shown the pattern, then asked to recreate the pattern on a blank slate.

“One interpretation of the strong relationship between Perception Span and batting performance is that the ability to store pitches in spatial working memory, and subsequently recognize them, helps batters avoid strikeouts and reach base more frequently,” wrote the researchers. “There may be evidence for this empirically, since pitchers obtain the highest strikeout rates and allow the lowest on-base percentage when seeing batters for the first time. Each time a batter faces a pitcher, his on-base percentage improves and strikeout rate declines, in part because he has ‘seen’ the pitcher’s repertoire before and filed it away into memory, making for easier recollection and recognition during subsequent meetings.”

In addition, BB% was also correlated with test results for Depth Perception, Eye-Hand Coordination and Reaction Time.

“The observation that Eye-Hand Coordination and Reaction Time are positively correlated with walk rate indicates that the ability to quickly react to visual stimuli is highly influential in a player’s ability to draw walks,” concluded the research team. “The positive relationship with Depth Perception supports previous findings indicating that binocular vision contributes to precisely projecting the location of a pitched baseball.”

Not too surprisingly, eye-hand coordination was also found to be a predictor of hitting success in another study by Dr. Daniel Laby of the Sports and Performance Vision Center, State University of New York College of Optometry. He and his team tested 450 professional baseball players during a spring training season using the eye-hand visual motor reaction time [EH-VMRT] test. They compared the results with specific measures of plate discipline, including walk rate and how often players swung at pitches in the strike zone.

Those players with the best hand-eye coordination also had better walk rates, getting a base on balls every 10 times at bat versus every 13 times for players with slower hand-eye performance.

In addition, those in the top 20% of the EH-VMRT were 6-7% more likely to swing at pitches in the strike zone, especially fastballs (versus off-speed pitches).

"One could hypothesize that faster EH-VMRT allows the batter an opportunity to be selective in which pitches he ultimately decides to swing at," wrote Dr. Laby and his team. "These timing differences may result in higher rates of swinging at pitches and a lower likelihood to gain a base on balls."

As teammates on the champion Red Sox, J.D. Martinez, no slouch of a hitter either, recognizes the decision making skill of Betts. "That's what he does," Martinez said. "He makes good contact, makes solid contact, and I think his mind is in the right place now where he's kind of lining up and kind of understanding the swing and the mechanics behind it to be able to drive the ball that way better." Martinez should know, he shows his plate discipline by leading the league in another advanced hitting stat, BABIP (Batting Average on Balls in Play), which is the rate at which the batter gets a hit when he puts the ball in play.

See the ball, hit the ball.