Alan Nathan is a professor of physics whose specialties include the physics of baseball. He is an expert on the aerodynamics of a baseball in flight and the science of the collision between bat and ball. He is writing a book and preparing to teach a Freshman Discovery course on the physics of baseball in Fall, 2007.
What is the gyroball, the supposedly mystifying new pitch thrown by Daisuke Matsuzaka, a new Boston Red Sox pitcher? Do you think it's for real?
The gyroball is a new pitch invented by a Japanese physicist based on elaborate computer simulations. The distinguishing feature of the gyroball is that it spins much like a football spiral or a bullet fired from a rifle. To understand the behavior of a gyroball, it is helpful to examine the forces acting on a pitched baseball. Principal among them is the downward force of gravity, which causes a baseball to fall approximately 3 feet on its sojourn to home plate. Also important is the so-called Magnus force on a spinning baseball, which always acts in the direction that the leading edge of the ball is turning. So what kind of break can one expect from a gyroball? The surprising answer is...none! When the spin is aligned with the direction of motion, as in the gyroball, the Magnus force is exactly zero. There is no left-right break and the amount of vertical drop is that due to gravity alone.
Does this mean the pitch is useless? Absolutely not! As the great left-handed pitcher Warren Spahn once said: "Hitting is timing. Pitching is upsetting timing." In some respects the gyroball looks to the batter like a typical fastball, yet it drops considerably more ââ,â perhaps 18 inches ââ,â so the befuddled batter swings over the ball. If the batter is successful in picking up the spin on the ball, it will appear to be similar to the spin on a slider, yet there will be no left-right break and once again the batter is fooled. So the gyroball is yet another pitch in the arsenal of a skilled pitcher. Is it a miracle pitch? Not really. Eventually batters will learn how to deal with it, and the traditional balance between pitching and hitting will be restored.
Will aluminum bats ever be used in professional baseball?
It is doubtful that Major League Baseball will ever allow the use of aluminum bats. The game of baseball has evolved over 150 years to be a delicate balance between pitching and batting. Whenever the scale tips in one direction or another, the rules are changed to bring the game back into balance. For example after the 1968 season in which pitchers dominated batters, the height of the pitching mound was lowered to restore the balance. It has been demonstrated conclusively that aluminum bats are a significantly better hitting instrument than the traditional wood bats. The ball comes off the bat faster, leading to more hits and especially more home runs. And the aluminum bat is considerably more forgiving on balls hit off the so-called sweet spot. The use of aluminum bats by MLB would dramatically alter the balance.
As an expert on the physics of baseball, you must have a sense of the most difficult skill in baseball. What is it and why?
There is no doubt that hitting a baseball is the most difficult skill in the game, perhaps the most difficult skill in any game.