A comparison of baseball and softball can be made as softball is directly descended from baseball and thus contains many similarities; however there are several pronounced differences.
Fastpitch softball is more popular in competitive leagues, especially at the college and international tournament levels, while slow pitch is more popular in recreational leagues where the relative skill levels of different players may vary widely. The different rules of slowpitch can be viewed as maintaining a competitive balance for less skilled players by eliminating certain strategies (e.g., base stealing and bunting) which require a high level of defensive skill to counter. Additionally, recreational leagues may impose their own ground rules, either for competitive balance or to meet local constraints (e.g., a time limit may be imposed on a game to ensure multiple games can be played in one day).
| Rule or Term | Baseball | Fastpitch softball | Slowpitch softball |
|---|---|---|---|
| Length of Game | 9 innings (7 in the high school level and in Minor League/college doubleheaders; 6 in Little League) | 7 innings (5 in certain college games) | 7 innings (5 in certain college games) |
| Equipment | |||
| Ball | |||
| 9 inches (229 mm) in circumference | 12 or 11 inches (305 or 279 mm) in circumference, less dense than a baseball | often same as fastpitch softball, special 14 or 16 inch (356 or 406 mm) balls rarely used, less dense than a baseball | |
| Bat | No longer than 42 inches (1067 mm). Must be made of wood at the professional level; may be made of aluminum in high school and college. | No longer than 34 inches (864 mm). Most commonly made of aluminum, though wooden bats may be used | No longer than 34 inches (864 mm). Most commonly made of composite materials, also aluminum, though wooden bats may be used |
| Field | |||
| Layout diagram | |||
| Baselines | 90 feet (27.43 m) | 60 feet (18.29 m) | Typically 60 feet or 65 feet (18.29 or 19.81 m); longer distances in some levels |
| Double first base | No | Yes, all levels under ISF, NSA and ASA. Used on a state-by-state basis in high school. | Allowed. Runner reaches safety base in foul territory, fielders make play at regular 1st base |
| Outfield fence | Variable distance from home plate is mandatory in professional and university leagues and optional in youth leagues. Many youth leagues, such as Little League, use a constant distance from home plate. | Constant distance from home plate (maximum of 250 ft/76 m) | Constant distance from home plate |
| Pitching distance | 60 feet, 6 inches (18.44 m) | Varies by level: 40 feet (12.19 m) (women's amateur), 43 feet (13.11 m) (women's high school, college and international) or 46 feet (14.02 m) (men) | Varies, typically 46 feet (14.02 m) |
| Pitcher's area | Raised sloping mound, radius of 9 feet (2.7 m), maximum height 10 inches (25 cm) | Flat circle, radius of 8 feet (2.4 m), marked with a white chalk circle | Pitching rubber only |
| Players | |||
| Defensive players in field | nine | nine (before 1946, ten) | ten (either a rover or shortfielder, or a left center and right center fielder) |
| Extra player | Designated hitter may bat in place of a defensive player (pitcher in some levels) and removes the defensive player from the game if the DH plays in the field. | Designated player may bat in place of a defensive player and, except in high school, removes the defensive player from the game if the DP plays in the field. | Extra player(s): although only 10 players may play on defense at one time, some leagues allow the batting order to include additional players, and possibly the entire roster. Defensive substitutions may occur freely provided the batting order does not change. |
| Batter | |||
| Bunting | Allowed. | Allowed. | Not allowed; batter is out if contact made. |
| Foul ball with two strikes | Batter is not out unless bunting. | Batter is not out unless bunting. | Batter is generally out. In many recreational leagues, a batter is allowed one foul ball with two strikes, with the second being an automatic out. |
| Hit by pitch | Awarded first base unless swing or no attempt made to avoid being hit. | Awarded first base unless swing or attempt made to intentionally be hit. | Not awarded first base. |
| Runner | |||
| Base stealing | Allowed at any time the ball is live (i.e. when "Time" is not called). | Allowed once the ball leaves the pitcher's hand; runners may not leave base if the pitcher has the ball within the circle. | Generally not allowed, although some levels may permit stealing after a pitched ball crosses the plate or touches the ground. |
| Taking a lead from base | Same rules as for base stealing. | Same rules as for base stealing. | Runner is usually permitted to take a lead after the ball leaves the pitcher's hand, but must return to base between pitches if the ball is not put into play. Runner can be called out for taking a lead before the pitch. |
| Pitching | |||
| Delivery | Any method; in practice, usually overhand. | Underhand; no speed or arc restrictions. | Underhand; must travel in an arc and within certain height restrictions (a common range is between 6 and 12 feet (1.8 and 3.7 m) above the ground). Umpire can call a pitch "illegal" while in flight. |
| Illegal pitch | Most infractions punished as a balk: the ball is dead, no change made to the count on the batter and all runners on base advance. With no runners on base, for some infractions, the pitch attempt is automatically a ball. | The ball remains live. If the batter reaches base successfully and all runners advance, no penalty; otherwise, the play is negated, the pitch attempt is automatically a ball and runners advance one base. | The ball remains live. If the batter does not swing, the pitch is automatically a ball. |