October 16, 2010

Scientists Deny Existence of Breaking Curveball: There's no such thing as a breaking curveball, claim researchers Arthur Shapiro of American University and Zhong-Lin Lu of the University of Southern California. The ball looks like it drops sharply, but it follows a smooth arc from pitcher to catcher. "It's always going to follow a parabolic path," Shapiro said. "But from a hitter's point of view, an approaching ball can appear to break, drop or do a whole range of unusual behaviors."

posted by rcade to baseball at 05:20 PM - 6 comments

Well, it is more that they say that a breaking curveball is an optical illusion rather than it not existing.

posted by Fence at 05:36 PM on October 16, 2010

Look up "parabola" in any math textbook, and you will see a curve that starts out almost flat, and then increases sharply in slope. Every pitch thrown follows a parabolic arc, but the slope at the time the ball reaches the batter is determined by the initial velocity of the pitch. When a pitcher attempts to throw a curve ball, he usually grips the ball so that it rolls off of his middle finger with the forefinger off of the ball. This will impart a spin in which the top of the ball is rotating toward the plate, while the bottom rotates away. Bernoulli's Principle means that the air pressure on the top of the ball will be greater than that on the bottom, and the ball will have a slight force in excess of that of gravity acting upon it. This will steepen the downward slope somewhat. The break on a curve ball is no optical illusion. Rather, it is the product of gravity and the force provided by Bernoulli's Principle. What makes it look so sharp to the batter is that the slope does not markedly increase until the ball is quite close to him. It is not an illusion, it really does drop, but to the batter, it does not look like an arc. Granted, the arc is smooth, but that does not mean there is no apparent break.

posted by Howard_T at 05:59 PM on October 16, 2010

"But from a hitter's point of view, an approaching ball can appear to break, drop or do a whole range of unusual behaviors."

And the batter is the one that the pitcher wants to fool, science be damned.

posted by roberts at 06:55 PM on October 16, 2010

"Are you sayin' Jesus couldn't hit a curveball because he never created a curveball?"

posted by wfrazerjr at 12:44 AM on October 17, 2010

I'm a little baffled by the article. When I was a kid I often heard it claimed that the curve ball was an illusion, which of course, was BS.

This article isn't claiming that the curve doesn't exist, but that it doesn't break, where break means a sharp change of direction. Did anyone actually believe this? From the side, and from a hitters perspective, a curve appears to break in that manner. But it only takes one view from behind the pitcher to show a curve follows a 'parabolic path'. The angle changes, the speed, the bite of the curve ball, all dependent on arm angle and spin, but the curve is exactly that, a curve.

They basically proved water is wet.

posted by justgary at 02:28 AM on October 17, 2010

This is contrary to what I remember reading about curves of soccer balls. A few years ago, a study concluded there can be a change in the path of a soccer ball. "This change from turbulent to laminar airflow, produces the sudden dips of the best free kicks as the ball approaches the goal, Carre said."

I think that this baseball study showed a non-breaking explanation for a breaking ball, and concluded that there is therefore no breaking in a breaking ball. The scientists that conducted this study are not physicists. One is in psychology and one is in cognitive neuroscience.

posted by Aardhart at 12:25 PM on October 17, 2010

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