Tiebreaker in sports

Association football
If a football match is drawn and a winner must be determined then ADG is played. In a 2-legged matches, if the aggregate score is tied, the team that scored more away goals wins, if it's stilled tied then it goes to ADG.

Laws of ADG explained by clicking this sentence.

In the and many domestic cups (e.g. FA Cup) and competition finals (FIFA World Cup (including semis), UEFA Euros, Champions League, UEFA Cup, Cup Winners Cup) the match doesn’t go straight to ADG instead one 20-minute period of extra time is played, 5 minutes after the 2nd half has ended (1 additional extra time sub is allowed). If a 2-goal lead is established the game ends and that team is declared the winner, if this does not happen, but a team leads at the end of ET period the leading team is declared the winner. If the deadlock is not broken it goes to ADG.

American football
It's "golden point", first team to score a point wins whether it's by touchdown, a field goal or a safety, no conversion follows after a touchdown. The regular season lasts for 10 minutes after if a team fails to score then it ends in a tie. However in the playoffs it's timeless.

Australian rules football
In the AFL, new rules were introduced for playoffs in 2016: if there is a tie at the expiry of regulation time, including in the Grand Final, two 5 minute halves of extra time are played with the teams swapping end after each half. If the match is still tied when extra time has expired, there is a 3rd untimed extra time period under sudden death rules, and the final siren will not sound until the next team scores.

Previous systems

Prior to 1991, if the scores were tied in a finals match after the final siren, the drawn final would be replayed on the following weekend, thus delaying all other finals by one week.

Due to various logistical issues that arose following the drawn 1990 Qualifying Final, the AFL replaced this procedure with extra time (with the exception of the Grand Final) in 1991. Until 2015, if the scores in a finals match were tied when regulation time expired, two five-minute halves of extra time were played until a winner was determined. This procedure was used twice: in the 1994 Second Qualifying Final between North Melbourne and Hawthorn (won by North Melbourne), and the 2007 Second Semi-Final between West Coast and Collingwood (won by Collingwood).

If the scores were tied after the final siren in the Grand Final, the match would be replayed on the following weekend.

Badminton
If the score reaches 20-20, then the game continues until one side gains a 2-point lead (such as 24–22), except when there is a tie at 29-29, in which the game goes to a golden point. Whoever scores this point will win.

Baseball and softball
If a baseball game is tied at the end of the usual 9 innings, the game continues into extra innings until an inning ends with a team ahead. Although games are occasionally ended as ties on account of weather or darkness (the latter happened much more often before lights were installed on most professional baseball fields in the 1940s), and some leagues (including Nippon Professional Baseball) allow only a limited number of extra innings before a game ends as a tie, professional baseball in the United States has no such limit. The longest Major League game in history (on May 1, 1920) lasted 26 innings, and a minor-league game in 1981 lasted 33 innings. In some venues, including international baseball, starting with the second extra inning, that inning may begin a full reset of the batting order to the coach's choice with up to two runners already on base, in order to increase the chances of a resolution.

Major League Baseball uses the term "tiebreaker" to refer to one or more additional games played after the scheduled end of the regular season between teams with identical win-loss records in order to determine participants in postseason play.

College, high school, and Canadian football
Similar to American football the only difference is a field goal or safety does not automatically win the game, instead the other team has possession of the ball to match the score.

Chess
In Chess, when two players play a match against each other and the score is even after the scheduled number of games, often there is a tie-break with games with faster time controls. In tournaments, when two or more players have the same final score, there can be a play-off but usually an auxiliary scoring system is used.

Cricket
The Super Over will commence 10 minutes after the main match. A coin toss will commence 9 minutes before the Super Over to determine who will bat or bowl first. Each team nominates 3 batsmen and a bowler for the Super Overs. For 1 over (6 balls), a team will bowl & field, while the other team bats, then they switch. The team that scores the most runs wins the Super Over and the match. Wickets can be taken as normal and a loss of 2 wickets ends a Super Over. If a super over ends in a tie the Super Over will be repeated until there is a clear winner. The team that batted 2nd in the previous super over will bat first in the next super over (if necessary). If the batsmen was out in the 1st Super Over he cannot be used until all 10 batsmen are used.

Field target
Field target — a precision air rifle shooting sport — uses either a sudden-death or shot count tiebreaker. The sudden-death tiebreaker (usually used to determine a single place such as 3rd when 3 awards are to be given or between two shooters) consists of each tied shooter (order dictated or decided by coin-toss or other technique) shoots at a target (typically a difficult shot such as ½" at 35 yards). If all shooters in the tie fail, then the target is moved closer. If one shooter hits, then the next shooter(s) who miss are out of the competition. If a round is complete with multiple ties remaining, the target is moved out (made more difficult) and the same procedure is repeated until only one shooter remains. This procedure can then be repeated to determine further placings among the losers of the previous round.

In cases where multiple places are to be determined (as in five people tied for first place), one approach is to have each shooter make several shots (n − 1 or more with n being the number of tied shooters). If all shooters miss all shots, the target is moved in (made easier); similarly, if all shooters hit on all shots, the target is moved out (made more difficult). If some variation in hits exists after a round, the top score gets the highest placing while those with identical scores can have a sudden-death shootout or a repeat of the multiple shot shootout (typically with a more difficult target) to determine other placings.

Futsal
2 periods of 5 minutes each are played, with teams changing ends in between. If the teams are still tied after the overtime, the match is decided with a penalty shootout.

Gaelic football and hurling
2 extra time periods of 10 minute are played, if a team is leading at the end of 1st period of extra time if the match is still tied after extra time then a third timeless extra time period commences, first team to reach or exceed 5 points (equivalent of a goal) wins.

Golf
If 2 or more players are tied at the top of the leaderboard, they will then replay holes there will be a 3-hole aggregate score playoff on Holes 16, 17, and 18. If the score is still even after that, a sudden-death playoff begins on No. 18, and it will keep going on until someone finally wins.

Handball
When a tie needs to be broken in handball, 2 straight 5-minute overtimes are played. If the teams are still tied after that, this overtime procedure is repeated once more; a further draw will result in a penalty shootout.

Ice hockey
Regular season or round robin: If a game is tied after regulation time (2 periods of 30-minute), the teams plays multiple sudden death 10-minute overtime periods, with 3 skaters per side + a goaltender (as opposed to the standard 5 + a goaltender). If regulation time ended while a powerplay was in progress, the team with the advantage will start overtime with more than 3 skaters (almost always 4, very rarely 5), and maintain its advantage for the duration of the penalty if no one scores. Similarly, if a team commits a penalty in overtime, the player is removed from the ice (or one of the skaters if the penalized player is the goaltender), but can be replaced, while the non-penalized team receives an extra skater for the duration of the penalty.

Playoffs or knockout matches: Following an intermission, multiple full 20-minute sudden death periods are played. Teams remain at full strength unless this is affected by penalties. If neither team scores, this procedure is repeated after the intermission. The teams change ends after each period. At 4th overtime period both teams will play 5-on-5, 5th overtime 4-on-4 and 6th overtime onwards 3-on-3.

Netball
2 straight 7-minute periods of extra time are played, with teams changing ends in between (with no break between periods). If the scores are still tied after the overtime, the match continues uninterrupted. Whoever establishes a 2-goal lead wins

Rugby
A coin toss will determine whether a team attacks or defends first, the attacking team will try to score, the try is started with a play the ball in the centre of their opponents 30 metre line with a full 6 tackle set. If a team scores by any method, the opposing team has possession of the ball (in the same place) and they attempt to either match the score or exceed it, failing to match it means Team 1 wins, matching it means play continues. If Team 2 exceeds Team 1's score Team 2 exceeds. After 10 attempts (5 attempts each) if there still is a tie then it goes into sudden death.

Tennis
At a score of 6–6, a set is often determined by one more game called a "12 point tiebreaker" (or just "tiebreak"). Only 1 more game is played to determine the winner of the set; the score of the resulting completed set is 7–6 or 6–7 (though it can be 6–6 if a player retires before completion).

Points are counted using ordinary numbering. The set is won by the player who has scores 7 points in the tiebreak and establish a 2 point lead. If the tiebreaker is tied at 6–6 then it continues until a player establishes a 2 point lead

The player who would normally be serving after 6–6 is the one to serve first in the tiebreak, and the tiebreak is considered a service game for this player. The server begins his or her service from the deuce court and serves one point. After the first point, the serve changes to the first server's opponent. Each player then serves 2 consecutive points for the remainder of the tiebreak. The first of each 2-point sequence starts from the server's advantage court and the second starts from the deuce court. In this way, the sum of the scores is even when the server serves from the deuce court. Players switch end after the 1st point and then after every 4 points

Snooker
If the scores are level when all the balls are potted in a frame of snooker all the balls are re-racked, a coin toss will occur and whoever wins it can decide whether to go first or second, normal snooker rules apply. If a player misses then his turn is over and the balls are re-racked and his opponent attempts to match or exceed his opponent's score, if he fails then Player 1 wins, if Player 2 matches the score but not excess the balls are re-raked and Player 2 sets a target for Player 1, if Player 2 exceeds Player 1's score then Player 2 wins.

Sumo
At the conclusion of a professional sumo tournament (本場所, honbasho), the winner of a division is the wrestler (力士, rikishi) with best record at the end of the 15-day tournament. If two or more wrestlers share are tied for the lead within a division, a series of additional playoff bouts will be held on the final day to determine the divisional champion. Restrictions against bouts between close relatives, members of the same stable, and previously faced opponents are lifted during a playoff situation.

Water polo
If the score is tied at the end of regulation play the game goes to penalty shootouts. In college play teams play 2 straight 3-minute periods, and if still tied multiple 3-minute golden goal periods thereafter. Same for high school, but may incorporate both methods.