Knuckleball Explained: What is It? And Other Useful Facts About Baseball’s Most Confounding Pitch


What is a Knuckleball?

The knuckleball is one of the rarest pitches in baseball, particularly if you only consider pitches that are part of pitcher’s expected pitch mix (e.g., not counting Zack Greinke’s eephus pitch that he throws a few times each season).

The pitcher’s goal when throwing a knuckleball is to eliminate as much as spin as possible from the ball. Without spin, the ball will flutter, or dance as announcers like to say, on its way to the plate. Though slow, this fluttering motion makes it difficult for batters to square up (put the barrel) on the ball.

Basics of Knuckleball Aerodynamics

I’m going to admit something: I don’t fully understand everything in this physics article that analyzed the aerodynanmics of the knuckleballOpens in a new tab.. In the conclusion, the authors do state that the knuckleball is “accompanied by complex flow physics”. An article published by IOPScience stats the “zigzag path is obtained provided a lateral unsteady symmetry of flow surrounding the ball exists”.

Something interesting from the latter article: “the obtention of a large knuckle effect requires a ball to be launched in a particular range of initial velocities corresponding to the drag crisis of the ball”. It appears that at least 50 m.p.h. is required to create the knuckle effect. The maximum velocity is limited because pitchers want enough time for physics to take over.

Visual aid:

And a fascinating Times graphic on knuckleball physics (found on Edward Tufte’s website):

Why don’t more pitchers throw a knuckleball?

An NPR article attempted to answer this question, and concluded that:

  • Some see it as a trick pitch, which may lead to it not being taught at younger ages
  • Requires precision (both in throwing the ball and in maintaining manicured fingernails
  • Due to the precision, it is much more difficult to throw than it appears

How hard is it to catch a knuckleball?

Quite difficult. There is a reason knuckleball pitchers often have a dedicated catcher. And even then, it’s expected that quite a number of passed balls will occurOpens in a new tab.. Josh Thole, Ryan Hanigan, and Jarrod Saltalamacchia are just a few catchers who have had the honor of trying to catch knuckleball pitchers.

Chart Showing Players with Most Passed Balls in a Single Season Since 2000. Jarrod Saltalamacchia with 26, Wilin Rosario with 21, Jason LaRue with 20, Geronimo Gil with 19, Russell Martin with 19, Ryan Hanigan with 18, Jorge Posada with 18, Gary Sanchez with 18, Josh Thole with 18, Josh Thole with 17, Tyler Flowers with 16, Yasmani Grandal with 16)
Data courtesy of www.baseball-reference.com

List of Knuckleball Pitchers

Any list of knuckle pitchers requires setting parameters. Some position players use a knuckleball when they are pitching, but most people (myself included) wouldn’t necessarily call them a knuckleball pitcher.

For my list, I am only including pitchers who pitched at least 100 games. These leaves out a few recent knucklers: Steven Wright (81 games from 2013-2019 but still active in minors), Eddie Gamboa (minimal MLB in 2016) and Ryan Freierabrand (minimal MLB in 2019).

Player Name MLB Start Year MLB End Year Games Played
Hoyt Wilhelm 1952 1972 1070
Phil Niekro 1964 1987 864
Charlie Hough 1970 1994 858
Joe Niekro 1967 1988 702
Eddie Fisher 1959 1973 690
Wilbur Wood 1961 1978 651
Dutch Leonard 1933 1953 640
Ted Lyons 1923 1946 594
Jesse Haines 1918 1937 555
Tim Wakefield 1992 2011 547
Eddie Cicotte 1905 1920 502
Tom Candiotti 1983 1999 451
Bob Purkey 1954 1966 386
R.A. Dickey  • 2001 2017 338
Jim Bouton 1962 1978 304
Steve Sparks 1995 2004 270
Mickey Haefner 1943 1950 261
Gene Bearden 1947 1953 193
Johnny Niggeling 1938 1945 184
Roger Wolff 1941 1947 182
Lew Moren 1903 1910 141
Dennis Springer 1995 2002 130

Recent knuckleball pitchers

2019: Ryan Feierabend
2019: Steven Wright
2021: Mickey Jannis

Best performing knuckleball pitchers

Four knuckleball pitchers have made the Hall of Fame: Jesse Haines, Ted Lyons, Phil Niekro, and Hoyt Wilhelm.

R.A. Dickey is the only knuckleball pitcher to win a Cy Young Award (2012 National League).

Seven knuckleball pitchers won at least 200 games in their career:

Player Name Win Loss Record
Phil Niekro 318-274
Ted Lyons 260-230
Joe Niekro 221-204
Charlie Hough 216-216
Jesse Haines 210-158
Eddie Cicotte 208-149
Tim Wakefield 200-178

Other Knuckleball Related Questions

Who invented the knuckleball pitch?

There is no definitive answer to that question, but Eddie Cicotte seems to receive the most credit.

Has a knuckleball pitcher ever thrown a no-hitter?

Several have come close, but so far, Hoyt Wilmelm (in 1958 against the New York Yankees) is the only knuckleball pitcher to throw a no-hitter.

Do catchers use different gear when catching knuckleball pitchers?

Catchers can! Glove manufacturers have produced over-sized mitts specifically to help catchers receive knuckleball pitches. For example, JustBallGloves advertises their knuckleball mitt as having an extra wide pocket and wide hinge channel to accommodate catching knuckleballs.

Other fun information about knuckleballs

Knuckler Charlie Hough started, and won, the first game ever player by the Miami Marlins (then called Florida Marlins).

Fun quotes about knuckleballs

Bob Uecker (Phil Niekro’s catcher in Atlanta): “The way to catch a knuckleball is to wait until it stops rolling and then pick it up”

Jason Varitek (Tim Wakefield’s catcher in Boston): “You know, catching the knuckleball, it’s like trying to catch a fly with a chopstick”

Willie Stargell: “Throwing a knuckleball for a strike is like throwing a butterfly with hiccups across the street into your neighbor’s mailbox”

Wesley Lyles

Wesley is a jack of all trades hobbyist. Though much of his spare time is spent playing board games (especially solo card games like Legendary), Hearthstone, Rocket League, and MLB The Show.e He also enjoys most sports, but pays way too much attention to baseball and football.

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