The Tiebreaker is a rule introduced by Major League Baseball during the 2020 season in order to end extra-inning games more rapidly. However the rule was already used in various other contexts before that.
The rule provides for each extra inning to begin with a baserunner (the so-called "designated runner") already on second base. The runner is the batter preceding the first batter of the inning in the batting order (with some variations in cases where the game is one in which there is no designated hitter). Any run scored by that runner, or by a runner who reaches base solely because he replaced said runner, is considered unearned.
There have been other variations of the rule used in other contexts, that differ from the MLB rule in some aspects.
In the 2008 World Junior Championship and 2008 Olympics, the IBAF introduced a new twist for the play of extra innings for that competition. If the game was still tied after the 10th inning, both teams then started the 11th inning with two runners on base - occupying first and second base. The manager was free to chose any players in the line-up as his runners, as long as they batted consecutively. The player following the two runners in the batting order then led off the inning at the plate. If a 12th inning was required, the batter whose turn was due came to the plate to lead off as scheduled, and the two batters that preceded him in the line-up started the inning on base, the batter before him on first base, and the batter before that on second. For example, if the 4th hitter was the last to bat in the 11th inning, the 12th inning would start with the 3rd hitter on second base, the 4th hitter on first base, and the 5th hitter at the plate. The objective was to encourage the scoring of runs in extra innings in order to bring the game to a quick conclusion.
This controversial rule has since been adopted in the Hoofdklasse and Cuban Serie Nacional, among other top level leagues. The rule was dubbed the Schiller Rule by American writer Peter Bjarkman in honor of former IBAF president Harvey Schiller, and the name has become commonly used in Cuba, The rule was also used in the 2017 World Baseball Classic, from the 11th inning on. In this case, the manager was not allowed to decide who would bat first in the 11th: it was up to the next scheduled hitter in the batting order to go first, with the two batters preceding him taking their place on first and second base.
In Organized Baseball
In 2017, Organized Baseball decided to test a similar rule in two low-level leagues, the Gulf Coast League and Arizona League; under this rule, each inning after the 9th started with the last runner to have completed a plate appearance in the 9th inning already on second base. The official explanation for the introduction of the rule was to test its practical implications and assess whether it could be adopted as a measure to speed up the game. In 2018, the rule was proposed for inclusion in the All-Star Game, starting in the 11th inning, and in spring training games in the 10th inning (spring training games were limited to just one extra inning). In both cases, the variation used was to start the inning with a runner on second base only. However, the change in spring training did not go through because of opposition from the Players' Association. But the rule was extended to the entire minor league structure of organized baseball that season, starting in the 10th inning (or in the 8th inning in case of a doubleheader), in order to avoid overlong extra-inning games; it had already been in place in certain independent leagues. In 2019, the rule was indeed put into effect in spring training, including in the 9th inning of certain tie games, with the prior mutual consent of the two teams. For the All-Star Game, its use was decreed starting with the 10th inning.
The rule was used in regular-season games during the 2020 season, as one of the changes motivated by the Coronavirus pandemic and the compressed season that resulted, along with the universal designated hitter and the introduction of seven-inning doubleheaders. While there was a lot of complaining initially about how this distorted the game, opinions seemed to change as the season advanced and the rule led to some very exciting late-game situations, while avoiding overlong games that wreak havoc with teams' pitching staffs over an extended period. As a result, it was retained in 2021, still on a provisional basis, with the likelihood that it would become permanent after the negotiation of the next Collective Bargaining Agreement. Initial reports after the settlement of the 2021-2022 lockout were that it would be dropped, but a few days later, MLB and the Players Association confirmed that they had agreed to keep it.
In Japan, the most commonly used terminology for this rule is "tiebreak" in reference to Tennis/Volleyball tiebreak rules, being commonly used on most non-NPB levels.
In both the Spring and Summer Koshien (high school level) Tournaments, games used to last a maximum of 15 innings. If the score was still tied, the game would end in a tie and be replayed the next day, but from 2018, the Japan High School Baseball Federation decided on the following rules:
- - The tie break will be used beginning in the 13th inning. Innings will begin with runners on first and second and no out.
- - The batting order will resume where it ended in the previous inning.
- - If the game has to be canceled after the start of a tie break, the game will end in a tie and a rematch will be played on the following day (or at the earliest possible date).
- - If the game is still tied after the 15th inning, the game will continue, however, each pitcher will be limited to a total of fifteen innings. Pitchers that reach fifteen innings will only be able to continue playing as a position player.
- - The tie break will not be used during the final game. If the game is still tied after fifteen innings, then the game will end and a rematch will be played the following day (or at the earliest possible date). The tie break will be used for the rematch game.
- - The two runners on base at the start of tie break innings will not count as earned runs if they score. The two runners will not get credit for being on base. Stolen bases, caught stealing, runs, and left on base will count, as will other stats connected to the runners, like RBI and double plays.
- - There will be no complete games stats in case of tiebreak.
- - There will be no hitter stats in case of tiebreak.
In the Japanese industrial (JABA) level, the tie break starts from the 12th inning.
Effects on Strategy
It has been speculated that the Schiller/Tiebreak Rule gives the advantage to the visiting team, as the visiting manager can keep his closer for an eventual bottom of the inning after he takes the lead, an option not open to the home team manager. In practice, with the rule variation featuring two baserunners, the first batter called to the plate in an inning will almost always attempt a sacrifice bunt, with everyone in the ballpark aware of the strategy. If it is successful, it is almost guaranteed that the defense will issue an intentional walk to the next batter in order to load the bases. The true strategy only starts with the following batter, as the defensive team needs to decide whether they will play their infield in in order to cut off the potential winning run at the plate, or play further back in the hope of a possible inning-ending double play. The team at bat also has the option of laying down a risky squeeze bunt at that point. In the version adopted by MLB, with only one runner on base, the strategic options are more varied, as reflexively calling for a sacrifice bunt is only adapted in certain situations.
Some persons have proposed alternatives to the tiebreak rule. For example, Justin Turner has suggested holding a "home run derby" after the 10th inning, in order to prevent overlong games. In his proposal, akin to penalty shots in soccer or a shootout in ice hockey, each team would designate three players to take swings for homers until five outs are made. He added that his proposal would have been for the 2020 season only, if it were to contain a large number of doubleheaders as a result of games lost to the coronavirus pandemic. In the end, when an agreement was finally reached on starting the suspended season, MLB decided to use the tiebreak rule already approved for the All-Star Game and tested in the minor leagues, starting in the 10th inning, for that season only (although it was eventually extended to the following seasons as well).
- Chris Bumbaca: "Dodgers 3B Justin Turner wants HR derby to end MLB games instead of extra innings", USA Today, April 3, 2020. 
- Will Leitch: "5 reasons to the love automatic-runner rule", mlb.com, May 13, 2021. 
- Bob Nightengale: "Weird 11th-inning tiebreaker works for World Baseball Classic - but never for MLB", USA Today Sports, March 12, 2017. 
- Jorge L. Ortiz: "In testing drastic new extra-innings rule, MLB grapples with pace, tradition", USA Today Sports, February 9, 2017. 
- Joe Posnanski: "Extra innings can be too much of a good thing: Low Minors experimenting with beginning extra frames with runner on second", mlb.com, February 9, 2017.