A guide to rules changes in MLB (and sports) history

February 1st, 2023

The changes coming to Major League Baseball in 2023 -- the pitch timer, defensive shift limits and bigger bases -- are significant. Merely reading about them creates a feeling of unfamiliarity.

But are they unprecedented? Hardly.

Look back at the history not just of MLB but the other major North American professional sports -- the National Basketball Association, National Football League and National Hockey League -- and you’ll see that the new measures taken to improve the baseball product have a lot of parallels.

We can put these three 2023 changes into three categories and note how other rules changes made through the years and through the leagues had similar aims.


MLB: The pitch timer (15 seconds with the bases empty, 20 with runners on) is an effort to reduce dead time. You can actually go back to the very first season of MLB’s Modern Era -- 1901 -- and see the first such effort. That’s the year the rule was enacted to make foul balls not caught on the fly strikes (until the batter has two strikes). Previously, batters could foul off pitch after pitch after pitch, and at-bats could drag on for an eternity.

In 1909, MLB created a rule that pitchers must face a minimum of one batter. This was necessary because managers were employing a time-wasting trick in which they would announce the insertion of one pitcher, who slowly headed out to the mound and threw a few warmup pitches, while the pitcher that the manager actually intended to use warmed up in foul territory. In 2020, MLB took this a step further by imposing the three-batter minimum to reduce pitching changes and dead time. The 2015 batter’s box rule (requiring hitters to keep one foot in the box during their time at-bat) and installation of timers to measure the break between innings and pitching changes and the 2018 introduction of mound visit limits are other, recent efforts to improve the pace.

NBA: Basketball’s biggest and most obvious pace initiative was the 1954 creation of the shot clock -- a 24-second limit before a shot must be taken. This had a dramatic, immediate effect on scoring (points per game went up from 79.4 to 93.1) and tempo.

More recently, in 2018, the NBA put forth a sweeping series of changes aimed at improving pace, including reducing the shot clock to 14 seconds after an offensive rebound of a missed shot; reducing the number of team timeouts and limiting when they can be used; initiating delay-of-game violations for free-throw shooters who walk behind the three-point line between attempts and teams that aren’t ready to resume play at the end of halftime; and starting the 15-minute halftime clock immediately when the second quarter ended.

NFL: As with the NBA, the introduction of a clock (in addition, of course, to the actual game clock) sped things up. The NFL play clock was initiated in 1976. It began as a 30-second clock, though it has since increased to 40.

Beginning in 2014, the NFL kept the clock rolling after a quarterback was sacked. In 2017, it reduced commercial breaks from five or six per quarter to four per quarter (though the breaks themselves did increase in length by 30 seconds). The league also standardized the re-start of the clock after a runner goes out of bounds as well as the length of halftime.

NHL: As far back as 1928 -- the 12th season of its existence -- the NHL began imposing delay-of-game penalties to players who pass the puck back into their defensive zone. Today, such penalties are imposed for a variety of offenses, including shooting the puck out of the playing area from the defensive zone, intentionally keeping the puck behind the net for more than a minute, etc. The 1943 introduction of the red line at center ice was the NHL’s effort to improve the pace of action, as it reduced offsides penalties. And in 1975, the league began allowing only the captain and his assistants the right to argue with referees, in order to prevent delays caused by persistent player protesting.

The biggest pace change came in 2002, with the institution of “hurry-up” faceoff and line-change rules. From the time the whistle blew to stop play, teams had 18 seconds to get into position before the puck was dropped. The result in the first season was a 15-minute reduction in game times.


MLB: The bigger bases, which have gone from 15 inches to 18 inches square, are primarily a safety issue, giving players more room to operate around the bases (especially at first base, where the fielder will have more room to make the catch while avoiding the charging runner). So in that regard, you could compare it to a number of equipment changes, such as the introduction of helmets in baseball, hockey and football.

But you can also compare it to past alterations to the game’s dimensions. In MLB, the minimum home run distance was initially set at 250 feet in 1925 and then increased in 1959 to 325 feet down the lines and 400 feet to center field. Also, the mound height was limited to 15 inches in 1903 and then further lowered to 10 inches in 1969. And while the strike zone is obviously not a physical object, the way it is called (ergo, its dimensions) has been adjusted many times in MLB history -- shrunk in 1950 (armpits to top of knees), expanded in 1963 (top of shoulders to the knees), shrunk again in 1969 (armpits to knees again), clarified in 1988 (midpoint between shoulders and top of the uniform pants to the top of knees) and expanded slightly again in 1996 (midpoint between shoulders and top of pants to a point just below the kneecap).

NBA: In efforts to curb the impact of dominant big men such as George Mikan and Wilt Chamberlain, the NBA twice expanded its lane in its early years -- from six feet to 12 feet in 1951 and from 12 feet to 16 feet in 1964.

And then, of course, there was the 1979 addition of the three-point line, which forever changed the sport. The league experimented with moving the line closer to the basket for a few years in the mid-1990s before moving it back to its original distance in 1997.

NFL: In its 14th season of existence, in 1933, the NFL moved the goal posts from the back of the end zone to the goal line to increase the number of field goals and decrease the number of tie games. The posts were then moved back in 1974 as part of a wider effort to create more touchdowns.

In 1972, the league moved the hashmarks to their present-day location (70 feet, 9 inches from the sidelines) in order to boost offenses by widening the short side of the field. The number of 1,000-yard rushers doubled that year.

NHL: The aforementioned creation of the red line in 1943 was a physical change that dramatically improved the action and the scoring, birthing the modern game. The NHL moved its goal lines, blue lines and defensive face-off circles in 1990 to give players more room to operate (and increase offense).

In 2005, as part of a variety of rule changes aimed at speed and excitement, the league again moved the goal lines and blue lines (while no longer utilizing the red line to prevent teams from making two-line passes) to reduce the neutral zone to 50 feet and again provide more room to create offense. The NHL has also used various net designs (including multiple changes to how the net is anchored to the ice) to address player safety over the years.


MLB: Beginning in 2023, a minimum of two infielders must be on each side of second base, with cleats in the dirt as the pitch is delivered. While MLB has never previously put limits on defensive shifts, this change is in keeping with other efforts through the years to improve the balance between offense and defense.

The aforementioned mound and strike zone changes in 1969 and the 1973 adoption of the designated hitter rule in the American League (since permanently extended to the National League in 2022) are certainly the biggest changes in that regard. There was also the 1920 outlawing of the spitball, the 2020 arrival of the three-batter minimum and the 2022 arrival of roster limits on the number of pitchers a team can carry that fit this theme.

NBA: Though it had made previous efforts to increase enforcement of the hand-checking rule that polices aggressive defense (using the hands to push, hold, slap and slash the offensive player), a 2004-05 measure to strictly forbid hand-checking was the real game-changer, freeing offensive players up to operate. The NBA also enacted the flagrant foul penalty in 1990 to reduce the amount of physicality defenders could use.

Way back in the 1940s, the league banned zone defense, only to allow it in 2001 in order to increase ball movement. In that same 2001-02 season, the NBA instituted a three-second limit for defenders to stand in the lane. 

NFL: From the early adoption of a roughing-the-passer penalty to a 2018 rule that a defender could not land with his full body weight on the quarterback or hit him in the head or below the knees, multiple efforts have been made over the years to protect the QB.

The 1970s were a particularly important period in the NFL opening up its passing game and improving offense, in general. In 1974, punting teams were prohibited from moving downfield until after the ball was kicked, penalties on offensive players for holding, illegal use of the hands and tripping were reduced from 15 yards to 10, and defenders were limited to chucking receivers only once after the receiver had gone three yards downfield. Beginning in 1978, defenders were permitted to make contact with a receiver within only five yards of the line of scrimmage. 

NHL: The mere legalization of forward passing in the 1920s was an amplification of offense/limitation of defense. The icing rule, which stops play and forces a faceoff when teams with a lead try to run out the clock by shooting the puck from their defensive zone all the way past the goal line, was instituted in 1937. 

But more recently, in 2005, the NHL took on a “zero tolerance” stance on all obstruction penalties, such as interference, holding and hooking, so that the league’s most skilled players could display their talents. 

The above is evidence of what a moving target the rules tend to be and how sports leagues are consistently trying to respond to athlete evolution and changes in entertainment tastes.

Unfamiliar? Maybe. Unprecedented? Hardly.