FROM THE MOUND
“When the batter walks up to the plate, it’s about mixing him up, keeping him off balance,” says San Francisco Giants pitcher Tim Lincecum. “I try to stick to my strengths and avoid theirs: that’s the art of pitching in itself. I think the things that mask pitches the best are consistencies in the mechanics [of the throwing motion]. The more you do the same mechanics, the less chance they have of telling what your pitch is. Everything comes out of the same arm slot, and it looks like the same pitch.
“I think the X factor is knowing that there are so many variations to get people out. It feels almost like a chess game. No matter what move you make, you can always kind of make the batter move around that.”
FROM THE LAB
“The more unpredictability from a pitcher, the harder the batter finds it to hit the ball,” says Professor Thomas Schrefl of the St. Polten University of Applied Sciences and the University of Sheffield. “The variation in pitch trajectory is explained by the Magnus effect.
“The spin of the ball creates an extra force in the air around it, which then alters the ball’s movement. Depending on how the ball is pitched, its speed will be between 70 and 100 mph and it will rotate at up to 2,000 rpm. The pitcher holds the ball in his thumb, index finger, and middle finger, and when he pitches, the thumb comes off the ball about 5.5 thousandths of a second before the index and middle fingers. In that short space of time, the index and middle fingers roll over the ball and cause it to spin.
“Thereafter, a point on the surface of the ball is moving around the center of the ball at a speed of about 16 mph. If frequency, f, is the number of rotations per second, then at 2,000 rpm, f ≈ 33. The rotational speed is the product of the angular speed 2πf and the radius of the ball (r = 1.44 inches), which here = 24.6 ft./sec.
“As the index and middle fingers roll over the ball before it is released, there are two forces working on the ball: the axial force, FA, makes the ball accelerate forward, while the frictional force, FF, produces torque. If the pitcher spins the ball at a 30° rotation angle and with a 90 Newton frictional force, the ball may achieve the aforementioned 2,000 rpm. (90N is slightly less than the weight of a mass of 2.2 lbs.)
“If the ball has backspin, the turbulence behind the ball flows downward. Due to the conservation of momentum, an upward force is exerted on the ball. The spin deflects the ball upward. The ball can be deflected in a number of directions depending on the position of its rotational axis, with deviation reaching up to 17.7 inches from the horizontal.”
Check out the July 2012 issue of Red Bulletin magazine (on newsstands June 12) for more articles. To read the magazine on your iPad, download the Red Bulletin iPad app.