My father remembers well the first time he saw a curveball: at the time he was a mere 13 years old, and a pretty good hitter as he recalls it. That year he was selected to play in the league all-star game, lending some credence to his remembered skill, and on the mound for the other team was a tall right-handed youth who appeared a bit older and bigger than the other players.
When he first came up to bat, my father recalls that the pitcher “had good speed on his fastball, and I managed to foul the first one off.” He took a ball outside to even the count, and then watched in disbelief as the next pitch came straight for his head!
He quickly dove to the ground to avoid getting beaned, then was shocked to hear the umpire’s declaration of “strike two!” rise above the billowing dust. He thought the umpire had made an awful call, and angrily dusted himself off to face the pitcher anew.
The next pitch was also thrown at his head, and again he hit the deck. When he heard “strike three!” announced, he looked up to see the pitcher grinning at him. “I had experienced my first curveball,” my pops lamented.
So just how much does a curveball really curve? That is the question that a group of researchers led by Arthur Shapiro of American University and Zhong-lin Liu of the University of Southern California set out to solve when they wrote this scientific paper back in 2010.
This study came out one year after the same group won an award for best illusion, and was published on PLoS ONE. Their illusion won the award at Vision Sciences annual meeting for demonstrating how an object that is traveling in a straight line can appear to curve, break, or otherwise drastically change direction.
In the experiment they conducted, five participants were set up in front of a computer screen on which floated two disks generated by Adobe Flash. One of these disks was blue and remained stationary, while the other was composed of rotating blue and white stripes to mimic the movement of a curveball.
When instructed to concentrate on the disk that was in motion, participants reported seeing it move in a more-or-less straight line, but this perception changed once they shifted their focus. When looking at the still disk, they saw the spinning disk veer off the straight line. And when told to switch between the disks, they reported seeing the one in motion behave even more erratically.
The work was first published in May 2009, and at the time received some very negative responses. Zhong-Lin Liu said that “some news media took out ‘the break’ from their stories and reported only that ‘Scientists took curveball away.’” He explains that this mangled headline elicited a flurry of negative responses from baseball fans and players alike, many of them people like my father who had once been fooled by a curveball and bit the dust.