The rules have evolved from the original Knickerbocker Rules in 1845, to the first set of National League rules in 1877. Since those years, some major changes and rule additions have taken place and Baseball Almanac has, hopefully, listed them into an easy to understand timeline.
"Use of the DH takes something away from the game." - Chub Feeney
Knickerbocker Rule ChangesIn Chronological Order |
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Year | Changes Made To Official Knickerbocker Rules |
1857 | The game used to end after the inning in which a team reached 21 runs. |
Now it is a 9-inning contest and the higher scoring team wins. | |
No base can be made on a foul ball. | |
1858 | Called strikes are introduced. |
A batter is out on a batted ball, fair or foul, if caught on the fly or after one bounce. | |
1862 | Pitcher's box introduced' 12 feet by 3 feet. |
1863 | Bat size is regulated. |
Called balls and bases on balls introduced | |
Pitcher's box is now 12 feet by 4 feet. | |
The pitcher is no longer allowed to take a step during his delivery and he had to pitch with both feet on the ground at the same time. | |
Home base and pitcher's box must be marked. | |
1862 | Each base runner must touch each base in making the circuit. |
1864 | Out on a fair bound is removed and the "fly catch" of fair balls is adopted. |
1866 | Pitcher's box narrowed to six feet wide. |
1867 | Pitcher is now permitted to move around inside their box. |
1868 | Bat length limited to 42 inches. |
Pitcher allowed to lift feet when delivering the ball. | |
Pitcher's box is now made into a 6 foot square. | |
1870 | The batter-runner may overrun first base. |
1871 | The batter is officially given the privilege of calling for a low or high pitch (in practice since 1864). |
1872 | Ball size and weight are made smaller, to dimensions currently in use today. |
1873 | Batter's box introduced. |
Any player, umpire, or scorer who gambles on a game he takes part in shall be expelled from his club and the National Association. | |
Year | Changes Made To Official Knickerbocker Rules |
National League Rule ChangesIn Chronological Order |
|
Year | Changes Made To Official National League Rules |
1877 | Canvas bases 15 inches square were introduced. |
Home plate was placed in the angle formed by the intersection of the first and third base lines. | |
Player reserve clause was written into the contracts for the first time. | |
The base runner was out if hit by a batted ball. | |
The hitter was exempted from a time at bat if he walked. | |
1878 | The number of "called balls" became 9 and all balls were either strikes, balls or fouls. |
1879 | Player reserve clause was for the first time put into a contract. |
The pitcher had to face a batsman before pitching to him. | |
1880 | Base on balls was reduced to 7 "called balls." |
Batter no longer got a fourtth strike. | |
Front of pitcher's box moved to 50 feet from the center of home plate. | |
The catcher had to catch the pitch on the fly in order to register an out on a third strike. | |
1882 | Pitchers now allowed to throw sidearm. |
The "foul bound catch" was abolished and the pitcher could deliver a ball from above his waist. | |
1883 | Championships were to be decided on a percentage basis. |
Six "called balls" became a base on balls. | |
1884 | All restrictions on the delivery of a pitcher were removed. |
1885 | A granulated substance may be applied up to 18" from the bottom of the bat. |
Chest protectors worn by catchers and umpires came into use. | |
Home base could be made of marble or whitened rubber. | |
One portion of the bat could be flat (one side). | |
The pitcher's box was changed to 4 feet by 7 feet. | |
1886 | Stolen bases became an official statistic. |
1887 | The pitcher's box was reduced to 4 feet by 5 1/2 feet. |
Calling for high and low pitches was abolished. | |
Choice of innings given to home team captain. | |
Five balls became a base on balls. | |
Four "called strikes" were adopted for this season only. | |
Bases on balls were recorded as hits for this season only. | |
The batter was awarded first base when hit by a pitch. | |
Home plate was to be made of rubber only - dropping the marble type and was to be 12 inches square. | |
Pitcher must keep his back foot on the rear line of the pitcher's box (55.5 feet from middle of home plate). | |
Strike zone established between shoulders and knees. | |
Coaches were recognized by the rules for the first time ever. | |
1888 | A batsman was credited with a base hit when a runner was hit by his batted ball. |
Batter awarded a hit when a runner is out for being hit by batted ball. | |
The base on balls exemption from a time at bat was restored. | |
1889 | A sacrifice hit was statistically recognized. |
Four balls became a base on balls. | |
One predesignated substitute may be used at the end of any complete inning. | |
1890 | Two substitutes may be used and may enter at any time. |
1891 | Substitutions were permitted at any point in the game. |
Large padded mitts were allowed for catchers. | |
1893 | The pitching box was eliminated and a rubber slab 12 inches by 4 inches was substituted. |
The pitcher was required to place his rear foot against the slab. | |
The slab was moved from 50 feet to 60 feet 6 inches from rear of home plate. | |
The rule allowing a flat side to a bat was rescinded. | |
The requirement that the bat be round and wholly of hard wood was substituted. | |
1894 | Foul bunts were classified as strikes. |
Sacrifice hits limited to bunts and not counted as at bats. | |
The rule exempting a batter from a time at bat on a sacrifice was instituted. | |
1895 | A held foul tip was classified as a strike. |
Bats were permitted to be 2 3/4 inches in diameter and not to exceed 42 inches. | |
Infield-fly rule was adopted. | |
Pitching slab was enlarged to 24 inches by 6 inches. | |
Size of gloves limited except for catchers and first basemen. | |
1899 | Batter awarded first on catcher's interference. |
1900 | Plate changed from square to five-sided figure. |
Year | Changes Made To Official National League Rules |
Major League Baseball Rule ChangesIn Chronological Order |
|
Year | Changes Made To Official Major League Baseball Rules |
1901 | All foul balls not caught on fly counted as strikes until batter has two strikes. |
Catchers were compelled to remain continuously under the bat. | |
1903 | Height of the mound was limited to 15 inches higher than the level of the baselines. |
Foul strike rule was adopted by the American League. | |
1908 | Pitchers were prohibited from soiling a new ball. |
The sacrifice fly rule was adopted. | |
1909 | Relief pitcher must face at least one batter. |
1910 | Stolen base no longer credited when other runner in a double steal is thrown out. |
1917 | Earned-run statistics and definitions were added to the rules. |
1920 | All freak deliveries, including the spitball, were outlawed. |
Balk to be called if pitcher releases pitch while catcher is out of his box. | |
The failure of a preceding runner to touch a base would not affect the status of a succeeding runner. | |
The batter was given credit for a home run in the last of the ninth inning if the winning run was on base when the ball was hit out of the field. | |
The number of runs batted in were to be included in the official score. | |
Frivolous ninth-inning uncontested steals in one-sided games were were to be scored as defensive indifference. | |
1925 | The minimum home-run distance was set at 250 feet. |
1926 | Pitcher was allowed to use a rosin bag. |
Sacrifice hit awarded when any runner advances on a fly out. | |
1931 | Balls that bounce over the fence entitle batter to two bases. |
Balls hit over the fence are to be ruled fair or foul based on where they are when they leave the field. | |
Sacrifice flies eliminated. | |
Regulations referring to a batter contacting his own ball were clarified as was the area of bases awarded a batter when a defensive player threw his glove at a batted or thrown ball or in the case of spectator interference. | |
1950 | Home team must bat second. |
Mound must be 15 inches high. | |
Rules for determining winning and losing pitcher established. | |
Size of first baseman's glove/mitt regulated. | |
Strike zone redefined to from armpits to top of knees. | |
1953 | Players were to remove their gloves from the field (in 1954) when batting and no equipment was to show on the field at any time. |
1954 | Defensive interference was changed from an offense solely by a catcher to one by a fielder as well. |
No fielder could take a position in line with a batter's vision with the deliberate intent to in any way distract the batter. | |
Sacrifice fly rule was brought back, this time with a man scoring after the catch only. | |
1959 | Regulations were set up for minimum boundaries for all new parks, 325-400-325 feet. |
1963 | Strike zone enlarged to from top of the shoulders to the knees. |
1965 | The size of the catcher's mitt was regulated. |
1968 | The anti-spitball rule was rewritten and tightened up because of the wave of moistened pitches that floated plateward the prior season. |
1969 | The pitcher's mound was dropped five inches. |
The strike zone was shrunken to the area from the armpits to the top of the batter's knees. | |
The save rule was added to the official rules for the first time. | |
1971 | All major-league players were ordered to wear protective helmets. |
1973 | The rule on glove size and color was minutely outlined for standardization. |
The American League began using designated hitter for pitchers on an experimental basis. | |
1974 | The save rule was rewritten. |
Minimum standards for individual championships were outlined. | |
1975 | The ball was permitted to be covered with cowhide because of the shortage of horses. |
Suspension for three days became mandatory if batter were to hit a fair ball with a filled, doctored or flat-surfaced bat. | |
Current save rule was adopted. | |
1978 | Pitcher can't throw at the batter. |
1988 | Catchers must wear protective helmets while on defense. |
2008 | MLB adds limited (home run calls, fair or foul) instant replay to be in effect for all games starting on Friday, August 29th. |
2014 | Runner attempting to score may not deviate from his direct pathway to the plate in order to initiate contact with the catcher (or other player covering home plate). Catcher cannot block plate without possession of ball. |
2016 | Slides on potential double plays will require that base runners must make a bona fide attempt to reach and remain on base. |
2017 | Pitchers no longer required to throw four intentional balls to walk a batter. Manager may now ask the plate umpire to let the batter go to first base. |
2020 | Pitcher must face a minimum of three batters in an appearance or pitch to the end of a half-inning. |
Temporary / COVID-19 Pandemic Rules Added for Shortened Season: | |
Extra-inning runner on second base automatically. | |
Seven-inning doubleheaders. | |
The postseason expands to 16 teams. | |
Universal designated hitter. | |
2022 | Draft lottery implemented to discourage tanking. |
The National League officialy adopts the designated hitter. | |
The postseason expands to 12 teams. | |
2023 | Bases increase in size from 15 to 18 inches. |
Defensive shifts are banned. | |
Extra-inning runner on second base, from 2020 temporary rules, made permanent. | |
Pitch clocks will be used. | |
Pitchers are allowed two disengagements per plate appearance without penalty. | |
Year | Changes Made To Official Major League Baseball Rules |
Major League Baseball Rule Changes | Research by Baseball Almanac |
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