Fastpitch softball is played by two teams of nine players over seven innings. The pitcher throws underhand, usually with a windmill motion, from 43 feet at most high school, college and adult levels. Runners may leave their base once the pitch is released, and stealing and bunting are central parts of the game. Other key rules include the look-back rule, which controls runners when the pitcher has the ball in the circle, the dropped third strike, the DP/FLEX substitution option and run rules that end lopsided games early. Details differ between governing bodies, so this guide summarizes the common framework and highlights where codes vary.
Rulebook note: Fastpitch softball is governed by several rule codes, including NFHS for high school, NCAA for college and USA Softball and other organizations for youth and adult play. Rules are updated regularly, so always check the current rulebook for your league.
Core fastpitch rules
| Rule | Summary |
|---|---|
| Players | Nine on defense; the DP/FLEX option allows a 10th listed player |
| Innings | Seven; extra innings often use the international tiebreaker with a runner starting on second |
| Pitching | Underhand delivery, released with the hand below the hip, starting with the pivot foot in contact with the plate |
| Leaving the base | Allowed when the pitch is released |
| Look-back rule | Runners must commit to a base once the pitcher holds the ball in the circle |
| Dropped third strike | The batter may run to first if first base is open or there are two outs |
| Run rule | Common versions end the game with a large lead after three, four or five innings |
The field and equipment
Fastpitch bases are 60 feet apart, and the pitching distance is 43 feet at most older levels, with shorter distances for younger age groups. The pitching circle has a 16-foot diameter. The ball is usually 12 inches in circumference and yellow, with raised red stitching in many leagues. Bats must meet the certification standards of the governing body. Batters, base runners and on-deck batters wear helmets, and many leagues require face guards on batting helmets. Catchers wear full protective gear.
Pitching rules
Pitchers must follow detailed rules to deliver a legal pitch. Common requirements include taking a position with the pivot foot in contact with the pitching plate, presenting the ball with a pause, delivering the ball underhand with the hand below the hip at release, and making a continuous motion without stopping or reversing. Replanting the pivot foot and pushing off again, often called a crow hop, is illegal in most codes, while rules on leaping vary. An illegal pitch usually results in a ball to the batter and may award runners a base, although the offense may sometimes choose the result of the play instead.
Batting rules
Batters must remain in the batter’s box when making contact; a batter who hits the ball with a foot entirely outside the box, touching the ground, is typically out. A batter is out after three strikes, and a foul ball caught in the air is an out. With two strikes, a foul bunt is a strikeout. Batters hit by a pitch are generally awarded first base if they did not swing, the pitch was outside the strike zone and, in many codes, they tried to avoid it.
The strike zone
The strike zone in fastpitch softball covers the area over home plate between the batter’s armpits and the top of the knees in many codes, although some organizations define the upper and lower limits slightly differently. It is judged when the batter is in their natural batting stance. A pitch that passes through any part of the zone is a strike, even if it does not touch the plate on the ground. Umpires apply the zone consistently for both teams, and knowing your league’s definition helps hitters decide which pitches to swing at and helps pitchers plan their approach.
Fastpitch vs slowpitch
| Aspect | Fastpitch | Slowpitch |
|---|---|---|
| Pitch | Fast, underhand windmill | Slow, high-arcing underhand pitch |
| Players on defense | 9 | Usually 10 |
| Stealing | Allowed after the release | Not allowed in most codes |
| Bunting | Allowed | Not allowed in most codes |
| Pitching distance (adult) | 43 feet | About 50 feet in many codes |
Safety rules
Fastpitch includes several rules designed to protect players. Batting helmets are required for batters, runners and on-deck batters, and many leagues require face guards. Catchers must wear protective gear, and many youth leagues require catchers to wear it even during warm-ups. The double first base reduces collisions at first. Obstruction rules prevent fielders from blocking runners without the ball, and collision rules at home plate protect both catchers and runners.
Base running rules
Runners may leave the base when the pitcher releases the ball; leaving early is a violation that can result in the runner being called out. Runners can steal bases, and they may tag up and advance after a caught fly ball. The look-back rule requires runners who are off base when the pitcher has the ball in the circle to immediately return or advance. Many leagues use a double first base to reduce collisions. Obstruction and interference rules protect both runners and fielders.
Substitutions and DP/FLEX
Most fastpitch codes allow starting players to leave the game and re-enter once, in the same batting position. The DP/FLEX rule lets a designated player (DP) bat for the FLEX player, who plays defense only. The specific rules on how the DP and FLEX can switch roles or be replaced vary by code. Many leagues also allow courtesy runners for the pitcher and catcher.
Extra innings and run rules
If the score is tied after seven innings, extra innings are played. Many codes use the international tiebreaker, placing a runner on second base at the start of each half-inning to speed up the game. Run rules, also called mercy rules, end the game early when one team leads by a set margin after a set number of innings, such as a large lead after three innings or a smaller lead after five. Exact margins vary by code and level.
Common penalties
| Violation | Typical result |
|---|---|
| Illegal pitch | Ball to the batter; runners may be awarded a base |
| Runner leaves early | Runner called out; the pitch may be a no-pitch |
| Obstruction | Runner awarded the base they would have reached |
| Batter out of the box at contact | Batter called out |
| Look-back violation | Runner called out |
Step-by-step: understanding a half-inning
- The pitcher presents the ball and delivers a legal pitch.
- The batter swings or takes, and the umpire calls balls and strikes.
- Runners leave on the release and may steal or advance.
- After the play, the pitcher receives the ball in the circle, and the look-back rule applies.
- Outs accumulate through strikeouts, fly outs, ground outs, force outs and tags.
- After three outs, the teams switch.
Common mistakes
- Leaving the base before the release.
- Hesitating off base when the pitcher has the ball in the circle.
- Contact outside the batter’s box by slappers.
- Misunderstanding the dropped third strike rule.
- Confusing DP/FLEX rules across codes.
- Assuming all leagues use the same run rules.
Frequently asked questions
How many innings are in a fastpitch softball game?
Seven innings, with extra innings if the game is tied.
Can you steal in fastpitch softball?
Yes. Runners may leave the base when the pitcher releases the ball.
What is the pitching distance in fastpitch?
43 feet at most high school, college and adult levels, with shorter distances for younger players.
