Graphics system shows curve is more than spun tale of woe

June 13, 1991|By Josie Karp | Josie Karp,Evening Sun Staff

The question dates back to shortly after Abner Doubleday discovered what fun could be had with four bases, a bat and a ball. The answer lies in the futuristic technology of computer graphics.

Past and future will be brought together tomorrow when the Discovery Channel's Invention series takes over Memorial Stadium to prove once and for all that a curveball is more than an optical illusion.

The proof comes courtesy of Supervision, a computer graphics system created by the California-based Sportsight Inc.

With the aid of its graphics,Yale professor Robert Adair and former Orioles Jim Palmer ( the pitcher) Brooks Robinson ( batter) and John Stefaro ( Catcher), the Discovery Channel will take a half-hour look at the pitch that has been baffling hitters for centuries. The series premieres in October.

Adair, author of the book "The Physics of Baseball," says " a baseball curves just about the way it looks."

Adair uses the example of a righthanded pitcher throwing a "sandlot curve," one that does not have the dramatic vertical drop that a major-league pitcher can produce. "The pitcher spins the ball as he throws, so that the right hand side, the third base side, is going forward, and the left hand side, the first base side, is going relatively backward."

To illustrate the point further, Adair asks us to "imagine a bug on either side of the ball. The bug on the third base side feels a strong breeze, caused by air resistance, while the bug on the first base side feels no breeze." According to Adair, when the pitcher spins the ball, much more force is being exerted on the third base side than on the first base side and that pushes the ball sideways, toward first base, making it curve.

Orioles Ben McDonald and Gregg Olson, both of whom throw curves that can make opposing batters look foolish, admit to rarely thinking of the physics that contribute to their success. But when asked to discuss exactly how they throw a curve, both sounded somewhat technical in their explanations.

"The rotation causes it to go down," said McDonald, who has been throwing the curveball ever since a fellow little leaguer taught it to him when he was 12. "Some curves have a 12 o'clock to 6 o'clock drop to it, like Olson's, but most are like mine, they have a kind of 1 o'clock to 5 o'clock or 2 to 4 o'clock drop."

According to Olson, the key to his is keeping his arm up.

"In laymen's terms, when you throw a curveball, whether it be hard or slow, you need to stay with it. Usually, when people throw curveballs, and try to throw it hard, they don't compensate with their body, and it just spins. In order to throw the curveball you need to keep your arm up, because the curve is slower through the body. When I throw my curveball I step maybe six inches shorter in my stride than when I throw my fastball, which allows me to get over the top of the ball so I can throw it for a strike."

Amateur physics aside, Adair thinks that players are better left in the dark about what it is that they actually do.

"Of all the ways to learn to throw and bat better, the worst way is to study the physics of it," Adair said.

Brian Harris, president of Sportsight Inc., however, has to hope that major league baseball teams do not feel the same way. Supervision, the brainchild of Harris' brother, Michael, an aerospace engineer, can instantly capture the path of a thrown ball, calculate its velocity from the moment it leaves the pitcher's hand to the time it crosses the plate, calculate its lateral and vertical movement, and display it all graphically on a computer 1.5 seconds after the ball is thrown. All of this is done using a process called triangulation, a process similar to a missile-tracking system.

In the case of the curveball, Supervision can display two paths, one showing the way the ball would have traveled had the pitcher not applied any spin, the way a batter might see it, and another, displaying the way the curveball diverges from that path. Supervison also can store every pitch of a game for instant replay, display the location of every pitch thrown by a pitcher, and the way a batter has been pitched throughout an entire game.

Harris envisions Supervision as an instructional tool to be used by baseball teams and broadcasters alike. The two came in contact last night when Home Team Sports used Supervison during its telecast of the Orioles game. Orioles general manager Roland Hemond, who was to have gotten an in-depth look at what Supervision has to offer the Orioles this afternoon, made several trips from his private box to see Supervision in action.

At one time in the fifth inning, Hemond came over to validate whathe suspected -- that Royals starting pitcher Bret Saberhagen's velocity dropped significantly, from the low 90s to the low 80s, during the Orioles' five-run outburst.

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