The Physics of Why Baseballs Do What They Do

© SirKodiak (reprinted with permission)
Before explaining the different pitches in baseball, it may be important to understand what makes a baseball move as it does. The pitcher can apply two types of forces to the ball, the velocity vector and initial spin, plus set its initial point of release. Nature then begins applying forces to it, mainly gravity from the earth and drag from the air. Spin, combined with the drag (and amplified by the seams), causes the Magnus Effect, which causes a force to act on the ball perpendicular to the direction of travel. Lack of spin, combined with the seams, causes turbulance which give the knuckler and spitter to move about randomly (and scuff balls increase this turbulance). Sounds technical, but I will try to point out the basics in layman's term.
The Magnus Effect is the most difficult to understand, but can be descibed as such here: the ball will move in the direction of spin as seen from the catcher's point of view (PoV). Four-seam fastballs do not drop as fast as other pitches because the ball is spinning upward (from the catcher's PoV), thus fighting gravity's pull down [human's cannot spin the ball fast enough to actually neutralize or overcome gravity though]. Pitches that "sink" do so because the ball is spinning downward (from the catcher's PoV) and helping gravity pull it down. Pitches that move to one side or the other do so because the ball is spinning in that direction (from the catcher's PoV).

It is important to understand that air density plays a large role both in the Magnus Effect and in drag (both increase as density rises). Higher altitude lowers the air density, as does higher temperatures. On the other hand, humidity (water vapor in the air) reduces air density because water molecules have less mass than air molecules.

Introduction

The variables of every pitch include at minimum: grip, wrist motion (or lack of it), arm speed, delivery (overhand, 3/4, sidearm, submarine, underhand, etc), and release. Some pitches with different variables have the same general result.

A pitcher gets his power from the extension of his leg, rotation of his hips, rotation of his shoulders, extension of his arm, snap (or rigidity) of his wrist, and invariably his fingers - in that order. His accuracy and resistance to injury are also closely linked to these things and this order. Here is a nice pitcher of Chris Carpenter's pitching motion. Height, arm length, hand size, finger length, grip strength, as well as strength and flexibility of each of body part also play an important role. I've found, to my chagrin, that pitchers make good arm wrestlers.

Please visit these links to Popular Mechanics to get a better understanding of the above:
  1. The Mechanics of the Fastball by Jim Kaat
  2. The Mechanics of a Breaking Pitch by Jim Kaat
  3. The Mechanics of Baseball by Jim Kaat
  4. Take A Lesson From Champion Pitchers reprint from June 1949 issue
Jim Kaat is a retired pitcher with a very good resume and the articles are easy to read. They show various grips, explain Magnus Force (Effect) with graphics, and are generally interesting to a baseball fan.

A far as I can tell, pitches generally fall into 4 categories; fastball, breaking pitch, change up, and other. Sometimes different grips give the same effect, so terminology gets jumbled. Simply adding more pressure to one finger can drastically change a pitch.

Relative speed is generally:
4-seam fastball > 2-seamfastball > sinker > slider > slurve > curveball > changeup > knuckleball

Delivery and Grips

Official Rules: 8.00 The Pitcher from MLB.com covers the two legal pitching positions, the Windup Position and the Set Position, and a lot more.

There are many deliveries (arm angles, motions), but the most common are 3/4's and overhand today. Sidearm and submarine are not very common in Major League Baseball today, though seem to be popular in Japan. Underhand was common before the 1890s. As the arm angle drops, the pitches tend to have more lateral motion. Here are some links to pictures of each style:

3/4's 2 3 4
Overhand 2
Sidearm 2 3
Submarine 2

Grips vary greatly between pitchers. Some pitchers get different results from the same grip, while others use different grips to get the same effect. ThePitchingProf.com has some nice examples of grips.

Any examples referring to the batter will assume that a right-handed pitcher is pitching to a right-handed batter unless stated otherwise.

The Important Things

All the above, and much of what comes below is about speed and movement. They are the impressive things, they are the things everyone talks, they are the things that can easily be seen. To the young pitcher they are everything. To the long term, successful pitcher, they are only the frosting on the cake.

What counts most in the end, unless you are a spitballer or knuckleball pitcher, is control and being smart. Control comes in three forms:
  1. Not being 'wild out of the strikezone'
    This leads to walks, and walks are not only a free pass, but they don't give the fielders a chance to help and the fielders tend to become lackadaisical.
  2. Throwing pitches where they are supposed to be
    Only the four seamer can be effectively thrown high in the strikezone on a regular basis, other pitches need to be kept down.
  3. Not being 'wild in the strikezone'
    This is keeping the ball out of the middle of the plate, failure to do so means getting hit often and hard.

A smart pitcher does many things that others don't:
Take a look a Randy Johnson's stats, you can see this happening. He has always thrown very hard and and had great movement, but around 1993 he learned control and got smart.

Deception is another thing that can be important. A good changeup is a good changeup because the pitcher has control of it and because it has the exact same arm motion as the fastball. Keeping the same arm motion on all pitches is a form of deception, and generally makes control better. So is a motion that keeps the ball hidden from the batter as long as possible. 'Herky-jerky' and odd windups are also forms of deception. Not many pitchers excel in this area. Dontrelle Willis has a lot of deception in his motion.

Here is an article on Jamie Moyer that should help show that speed and movement are not all there is to pitching. From the article:
Quote:
"He just keeps you off balance. Even when he throws 80, he can still jam you to death," (Travis) Lee said. "He's got seven different changeups. And he's got three different sliders and four different curveballs. He's the master of the deception. And he's been doing it so long, he knows how to hit those spots. Just knows how to pitch."
Fastball (Cheese, Cheddar, Heat, Heater, Gas, Old Number One, Dart, Hummer)
The general category of the fastest pitches thrown. Ther are actually a fair number of people that can throw this pitch around 100mph, but few can control it well enough to be effective. Most pitchers throw their fastball in the 86-89mph range. Ones that throw it 92mph+ are usually considered hard throwers, whereas some are fine pitchers with a 84mph fastball. Some fastballs will have 'natural' movement (usually caused by the delivery) that match the descriptions below, but are actually another type. I am assuming when BBM2k7 uses the term for a pitch, they are not sure what type of fastball the player has and is using a 4-seam fastball.
  1. Four-seam fastball (fingers cross 4 seams)
    The fastest, straightest fastball that sometimes "appears to rise" when it is thrown above the belt due to spin causing it not to drop as quickly as other pitches. Only pitch that can be effective high/low, inside/outside. If you see a catcher 'giving the sign to the pitcher' with no one on base, and he puts down one finger (usually the index), this is the pitch that will be thrown. This is how most players try to throw the ball while fielding.

  2. Two-seam fastball (fingers run along 2 seams)
    A fastball that is slower that a four-seamer but has more movement, usually to the side and/or down; includes:
    1. Sinking Fastball (Sinker, Heavy Fastball)
      Equal pressure on both seams; ball has downward motion; must be thrown at bottom of stike zone to be effective
    2. Cut Fastball (Cutter) note: seems this was originally called a slider, and is still often called a "hard slider"
      Unequal pressure applied by fingertips; ball has both sharp sideways and downward motion; usually thrown inside, often breaks the bat or "cuts (breaks) the bat off at the hands" (can be thrown from various grips, but mostly as a two-seamer today). Mariano Rivera has has revitalized this pitch and perhaps throws the best one today.

  3. Split-finger Fastball (Splitter)
    Fingers spread wide, similar to cutter grip but fingers outside seams (like forkball); ball has a sharp downward motion; thrown at bottom of strike zone, often drops below strike zone with batter swinging over it for a strike. Bruce Sutter popularized this pitch.
    1. Slow Splitter
      Probably either a forkball or a splitter where the pitcher 'takes a little off' so he can use it as a change up by slowing arm speed or dragging back leg.
Some terms related to the fastball:
Changeup (Change, Change of Pace, Dead Fish)
The changeup is pitch that is ideally thrown with the same arm speed, arm motion, and arm location as the fastball; but due to a different grip, is considerably slower. There are 3 general types of changeups, plus hybrids, though some pitchers will use a slow curve or similar pitch as a change (some very hard throwers even use a splitter as a change)
  1. Straight Change
    Often thrown with 3 fingers on the ball and with the ball deeper into the palm of the hand, has trajectory similar to four-seam fastball but will drop more just because it is in the air longer

  2. Moving Change
    A changeup that has lateral movement, various grips can produce this effect
    1. Circle Change (Sinker-screwball)
      Usually thrown with a grip where index finger and thumb form a circle and pressed against the ball (like an 'OK sign') and can be thrown so action is like a screwball or a curveball, depending on wrist movement and grip, but most have screwball motion (break away from a left handed batter). Frank Viola popularized this pitch, though there seems to be some evidence it existed well before Viola's time. Many pitches called screwballs in the past may have been circle changes, and the refining of this pitched has made the true screwball almost non-existant today.

  3. Sinking Change
    A changeup that breaks down, like a splitter
    1. Forkball
      Grip is similar to split-finger, but held deeper in palm and fingers often even wider; speed differs by pitcher, thrown anywhere from changeup speed to near splitter speed; breaks sharply down. Sometimes called dropball. Joe Kerrigan was well known for his forkball and is teaching it to players today.
    2. Palmball (Four-finger changeup)
      Many different grips, but the common denominator seems to be that the ball is held deeper in the palm than a forkball, pressure is still applied with the fingers and not the palm; most break down, but some grips allow it to be a straight change
    3. Vulcan Change
      Grip is like the "vulcan sign" from Star Trek, index and middle finger together, ring and small finger together, wide gap between middle and ring finger; breaks sharply down

  4. Hybrids
    Many pitchers throw hybrid pitches, from fastballs to knuckle balls. For example, Eric Gagne throws this fosh/vulcan/circle change
    1. Foshball (Forkscrew)
      Thought to be invented by Mike Boddicker when he was trying to learn to throw a forkball; supposedly named by combining FOrkball and "dead fiSH" (i.e. changeup); pitch has slight rotation and breaks like a screwball with more downward movement

    Some terms related to the changeup:
    • Bugs-Bunny Changeup
      • a changeup that is very slow; or
      • a changeup with lots of movement
    • Slowball
      • another name for a changeup; or
      • a pitch where the ball is slowed down by slowing down arm speed or dragging back foot
Breaking Pitch
A breaking pitch is a pitch that moves, laterally and/or down, but has neither the speed of a fastball nor is as slow as a changeup. Curveballs are slower and break more than, but not as sharply as, sliders do.
  1. Curveball (Curve, Hammer, Hook, Uncle Charlie, Yakker, Deuce, Bender, Knee Buckler, )
    Curveball originally meant any pitch that moved and wasn't a fastball, then any pitched that moved and wasn't a fastball or changeup (what we call a breaking pitch today), then it refered to what we today call a 12-6 curveball, and today usually refers to a Roundhouse-type curve.
    1. Overhand Curveball (12-6 Curve, Dropball, Drop Curve, Overhand Drop, Downer, North-South Curve, Sinking Curve)
      Curveball that drops sharply down, ideally with no lateral movement, that is equally effective against batters from both sides of the plate. The spin is applied by snapping the wrist down very hard at release. Darryl Kile and Tom Gordon have been well known for this pitch recently.
    2. "Modern" Curveball (The pitch currently just refered to as a curveball)
      Curveball that is thrown 3/4 arm, and curves down and away from the batter. Usually only effective against batters that bat from the same side (RHP vs RHB, LHP vs LHB).
    3. Sidearm Curve
      Curveball that is thrown sidearm, and curves farther away from the batter than a Roundhouse Curve, but not as far down. Jesse Orosco is famous for this pitch.
    4. Roundhouse Curve (Dipsy-Do, Rainbow Curve, Sweeping Curve)
      Curveball thrown 3/4 arm and that is slower than a normal curve and has a wide, sweeping break both laterally and down.

    Some terms related to curveballs:
    • Hanging Curve a curveball that does not break due to lack of spin and tends to be caught by the fans in the outfield seats
    • Backdoor Curve a curveball that appears to be a ball until it breaks over the plate for a strike
    • Biting Curve a curveball with a sharp break

  2. Slider (Slide Piece, Hard Curve, Sailer, Nickel Curve)
    A breaking pitch that is faster than a curve (but not as fast as a fastball) but breaks less overall (but sometimes sharper and later). This is basically achieved by using an off-center fastball grip and snapping the wrist hard, though various grips are used. Considered a pitch that will damage a pitcher's arm, especially if thrown when young, due to the great amount of torque that occurs at the pitcher's elbow. Some organizations do not allow the minor league pitchers to throw it until they are in AA.
    1. Sweeping Slider (Frisbee Slider)
      Some pitchers, especially left-handed pitchers pitching to left-handed batters as it is normally very tough for them to hit, will drop down sidearm when throwing a slider (or always throw sidearm) to make it a slider with a great amount of lateral break. Randy Johnson is famous for doing this.

    Some terms related to sliders
    :
    • Hanging Slider a slider that does not break, tends to be hit hard like the hanging curve
    • Backdoor Slider a slider that looks to be a ball until it breaks over the plate for a strike
    • Backup Slider a slider thrown inside to the batter that appears as it is going to break off the plate for a ball but doesn't
    • Doorknob Slider a slider thrown with a twist of the wrist much like turning a doorknob to open a door
    • Tight/Dime Slider a slider thrown with a lot of both spin and speed
    • Hard Slider usually refers to a Cut Fastball, but could also be used for a slider that is 90+ mph (very rare)
    • Frisbee Slider usually a Sweeping Slider, but term has been used for a hanging slider as well

  3. Screwball
    A breaking pitch that breaks away from left-handed batters but is also known for shortening players careers due to the unnatural arm movement. Some of the early pitches called screwballs were probably actually circle-changeups. Carl Hubbell and Fernando Valenzuela were well known for throwing this pitch.
    1. Fadeaway
      Screwball-type pitch thrown by Christy Matthewson, probably the precursor to screwball.

  4. Misc.
    1. Slurve (Fast Curve, Short Curve)
      In some cases this is the name given to a curve thrown from the 3/4 delivery, and in others (more commonly) it is a pitch that is faster and breaks less than a curveball but slower and breaks more than a slider.
    2. Knuckle Curve (Spike Curve)
      Various meanings over time, like a fastball thrown using the knuckles instead of fingers (and acted like a spitball) and a pitch where ball was held in knuckles and pushed out of hand at last moment. Most known today as a pitch thrown by Mike Mussina that is a regular curveball with the index finger tip dug into the baseball.
Other
Various pitches that do not fit in the other categories.
  1. Spitball (Spitter)
    Fingers not on any seams and some slippery substance between fingertips and hide of ball; ball has minimal spin; sinks (and generally acts like a fast knuckleball). Spitballs were outlawed prior to 1920. There were official complaints about it as early as 1917 and was a hot topic in sports magazines before that. Gaylord Perry was last widely known spitballer.
    1. Dry Spitball (Dry Spitter)
      A bit of dry dirt (or another loose dry substance) is applied to fingertips to allow ball to slip out of hand and not spin. (Banned) There is a legal version where the pitcher just grips that ball so that none of his fingers touch a seam.
    2. Wet Spitball (Wet Spitter, Wet One, Unsanitary Pitch, Mudball)
      A bit of wetness (spit, vaseline, etc.) is applied to fingertips to allow ball to slip out of hand and not spin. Banned proir to 1920 season, though some pitchers were allowed to continue to throw it under a 'grandfather clause'
    3. Shineball
      Like a spitball, but the 'slipperyness' come from hide of baseball being made 'shiny' and slick due hard contact with a bat or fence, or purposely rubbed smooth, like on pant legs or belt. Also name given to pitch where pitcher darkened one side of the baseball (with dirt, tobacco juice, etc) and the wiped the other half until was very white and shined; this made ball hard to see when spinning. (Banned)

  2. Knuckleball (Knuckler, Butterfly Ball, Flutterball)
    Various pitches have at one time have been called knuckleballs, but today it refers to a pitch where the pitcher puts either the finger tips or knuckles of his first two fingers on the ball and throws it with as little spin as possible. This causes the ball to break unperdictably and generally 'wobble' along its path. The ideal knuckle is said to rotate once on its way to the plate. Tim Wakefield one of the few throwing this pitch today, and his fansite has many pictures of him throwing it. One important thing about knuckleballers is they basically don't get tired because minimum effort is exerted, and they do not need much rest.
    1. Fast Knuckleball
      A knuckleball thrown hard, probably about the speed of a slider, with fastball arm speed.
    2. Slow Knuckleball
      A knuckleball thrown softly, sometimes as slow as 50-60 mph. Could be attained through slowing arm speed, dragging back foot, or grip.

    Here is an article that talks about the physics of the knuckleball in almost layman's terms. Some great quotes about and pictures of, as well as grips of the knuckleball. Nice page titled Knuckleball 101.

  3. Eephus
    A high arcing, slow lob pitch, like slowpitch softball but overhand.

    According to Paul Dickson's The Baseball Dictionary, the "eephus pitch" was first used by Pittsburgh Pirates starter Rip Sewell. In an exhibition game against the Detroit Tigers in 1942, Pirates catcher Al Lopez called for a changeup on a 3-2 count to Dick Wakefield. Sewell threw a high, arching lob to the plate, and when the pitch finally arrived, Wakefield swung and missed. After the game, manager Frankie Frisch asked Sewell what he called the pitch, and Pirates outfielder Maurice Van Robays replied "that's an eephus pitch." When Sewell asked him what an eephus was, Van Robays said, "Eephus ain't nuthin'." From then on, Sewell called it the eephus pitch. Sewell said he created the pitch after a war injury forced him to alter his wind-up. Unable to pivot on his right foot, he had to adopt an overhand delivery which led to the development of his new pitch.

    My most memorable moment with the eephus was a game between the Expos and Astros. Pascual Perez had an eephus he called the "Pascual Pitch". He made the mistake of throwing it to Glenn Davis. Davis just happened to be some professional softpitch leagues all time home run hitter. The ball looped in, and Davis crushed it down the left field line to the back of the top deck (3rd or 4th deck, don't remember) in Olympique Studium near where the dome part of it began.

    Steve Hamilton called his the Folly Floater. Bill "Spaceman" Lee called his a Bloop Curve. Dave LaRoche called his LaLob. Current pitcher Casey Fossum calls his the Fossum Flip. Current pitcher Orlando "El Duque" Hernandez also seems to have one that is called "El Droppo"

  4. Scuffball (Cutball, Emeryball)
    A pitch thrown where the surface has been scuffed, cut, or otherwise marred by use of sandpaper, emeryboard, sharpened belt buckle, etc. Used to give the pitcher a better grip for a sharper breaking ball and/or move erracticly due to disturbance of the airflow. (Banned)

  5. Gyroball
    I'm not describing it, but here is an article from the online expansion of the Neyer/James Guide to Pitchers. It is from Japan and it is funky. P.S. If my 'guide' even slightly interests you, do yourself a favor and buy the book. By far the best page with links to the gyroball I have seen is here.

  6. Incurve/Inshoot (term used 1890s-1930)
    Both terms often meant same thing, a fastball thrown 3/4 or sidearm (not overhand). I have a feeling that it was thrown 'crossfire', which means the batter stepped towards the on-deck circle rather than home plate. Sometimes incurve meant a screwball-type pitch.

  7. Outcurve (term used 1865-1920s)
    Acts like a curveball thrown 3/4, sidearm, or submarine. Here is how Lefty Grove threw what was called an 'Out drop curve ball':
    Name:  grove, out drop curve ball how to.JPG
Views: 9769
Size:  57.5 KB
    Thanks to robinhoodnik

  8. Raiseball
    Underhand fastball that actually did rise coming to the plate because of angle of release

  9. Puffball
    Gaylord Perry again. He figured since the 'resin bag' was allowed on the mound that he would use it. He covered the ball in the powder and then pitched, causing a 'puff of smoke' when he released it that distracted the batter. It was almost immediately banned.

And for those that would like to know a little bit more about those that used banned pitches (and some other cheats in baseball), there is this from ESPN.

Other Pitch Terms