Friday, June 27, 2014

The Knuckleball

knuckleball (or knuckler) is a baseball pitch with an erratic, unpredictable motion. The pitch is thrown slowly with a special finger grip to minimize the spin of the ball in flight. The slight rotation causes voritces over the stitched seams of the baseball during its trajectory, which in turn can cause the pitch to change direction making it very difficult to hit and catch. 

Knuckleball 101 - Blog
- Learn how to throw the knuckleball 

As used by Eddie Cicotte, the knuckleball was originally thrown by holding the ball with the knuckles, hence the name of the pitch. Now the knuckleball grip includes digging the fingernails into the surface of the ball or gripping the ball with the finger tips.

Is there an ambidextrous pitcher who can throw a knuckleball?

Watch Switch Pitcher Henry Knight throwing the knuckleball.

Great knuckleball pitchers:
Tom Candiotti, Charlie Hough, Phil Niekro, Joe Niekro, Hoyt Wilhelm, Wilbur Wood

Recent pro knuckleball pitchers:
R.A. Dickey, Tim Wakefield (retired)

Tim Wakefield's Knuckleball (video)
Wakefield talks about how he grips and throws the knuckleball.

Tim Wakefield throw knuckleball in game (slow motion video)
The batter swings and misses a knuckleball, while the catcher closes glove and misses the ball.

College knuckleball pitchers:
Andrew Kelley LHP - Grinnell College (watch video)

Little League knuckleball pitcher:

E:60 Chelsea Baker - ESPN Video July 20, 2010 - 10 min

In 2010, the best player on the Plant City Little League Team, was a 13-year-old girl named Chelsea Baker. The young knuckleball pitcher dominated the boys using a pitch she learned from Joe Niekro - a former major league pitcher who mastered the knuckler.

Quotes from pro players

"Trying to hit that thing is a miserable way to make a living." - Pete Rose

"Trying to hit Phil Niekro is like trying to eat jello with chopsticks. Sometimes you get a piece but most of the time you get hungry." - Bobby Murcer, on Phil Niekro

"You don't catch the knuckleball, you defend against it." - Joe Torre

"There are two theories on catching the knuckleball...
unfortunately, neither of the theories work." - Charlie Lau

Science behind the Knuckleball

When a pitcher throws a knuckleball, the ball has no rotation and appears to flutter. What makes it flutter?
Porter Johnson, a physics professor at the Illinois Institute of Technology and an avid baseball fan, supplies the answer here.

"For a knuckleball, the important thing is that the ball rotate about an axis so that the seams are on one side of the front of the ball at one instant, whereas a little later they are on the other side of the front of the ball. The ball will then drift in the direction of the leading seam, and then drift back when the seam becomes exposed on the other side.
The seams produce turbulence in the air flowing around the ball, disturbing the air layer traveling with the ball and thereby producing a force on the ball. As the ball slowly rotates, this force changes, causing the ball to "flutter" and slowly drift. The knuckleball is very difficult to throw well and is sensitive to wind, temperature and, of course, atmospheric pressure."
The break on the knuckleball
One of the most interesting statistics measured is the break of a much up-and-down and side-to-side motion a pitched ball goes through after leaving the pitcher's hand. The break demonstrates why the knuckleball is such a difficult pitch to hit, particularly when used in conjunction with other pitch types.

The Physics of Baseball 2: "The Seven Per Cent Knuckleball"
The knuckleball is a different creature altogether. It is, first of all, a misnomer: the knuckleball is actually propelled by the fingertips, or the ends of the fingers if the pitcher has accidentally lost his fingertips. The knuckler is thrown without spin, causing asymmetric stitch configurations and trajectoral turbulence relative to the ball's flight. The wind resistance is directed from the smooth side of the ball to the rougher, stitched side. Therefore the balance of Magnus forces is thrown into imbalance, and the ball's flight is given over to chaos theory.


  1. Check out my new blog - Knuckleball 101

  2. Thanks for the videos and links.