Interchange numbers
AFL
As of the 2021 season, at AFL level, each team is permitted four interchange players, and a maximum of seventy-five total player interchanges during a game; players have no limit to the number of times they may individually be changed, and an interchange can occur at any time during the game, including during gameplay. Additionally, a fifth bench player is designated a medical substitute, allowed to take the field only to permanently replace a player deemed medically unfit to continue; except with permission from the AFL Medical Officer, a player thus substituted off would be ineligible to play again until at least twelve days later. The players named on the interchange bench and as the substitute in the teamsheet, which is submitted ninety minutes before the commencement of the game, must be the interchange players who start on the bench, however they may be substituted immediately if the coach wishes.Other leagues
Interchange rules are not uniform across all leagues. In the major state leagues, as of 2016, following interchange numbers are permitted: * South Australian National Football League: three interchange players, with a maximum of fifty rotations per team per game. *Substitutes
At different times during the history of the sport, there have been ''substitute'' players (also known as ''reserves'') serving a function distinct from interchange players. A player who begins the game as a substitute may take no part in the game until he is substituted for another player, the latter of whom permanently leaves the field. The substitute rule was resisted for many years, with the prevailing view in the 1910s and 1920s being that a team should be permitted only to substitute a player in the event of an injury, but that there was no practical way to rule against a team making a tactical substitution. A single substitute, known as the nineteenth man, was finally introduced by the Australian National Football Council for the 1930 season, with no restrictions on whether the substitution be used for injury or tactical reasons. A second substitute, the twentieth man, was introduced in 1946, before the substitutes were replaced by interchange in the 1970s. Additionally, in the AFL between 2011 and 2015, a hybrid interchange–substitution arrangement existed in which there were three interchange players and one substitute; under those rules, the substitute was required to wear a green vest until activated, and the player substituted out of the game donned a red vest. A true medical substitute was introduced in 2021, which for the first time placed a formal restriction on using the substitute for medical reasons only, by restricting the return date of the player substituted off.Interchange protocol
In front of the interchange benches is the ''interchange area'' (sometimes called the ''interchange gate''), which is a 15-metre stretch of the boundary line, roughly centred between the two teams' benches, through which all players must enter and exit the ground when being interchanged. It is marked on the boundary line with two short lines, perpendicular to the boundary, and sometimes with a slanted end. A player who interchanges outside of this area is not permitted to return for the rest of the game. Where a player leaves the ground on a stretcher, he is permitted to take the most direct route to the changerooms for medical treatment, and is still permitted to return later in the game; however, where he leaves on a stretcher, the player must wait for 20 minutes of playing time (the length of one regulation quarter) before returning. If a stretcher is brought onto the ground but the player ultimately does not need to use it, he must still wait for 20 minutes before returning. Due to new AFL concussion rules, effective from 2011 onwards, any player suspected of suffering a concussion must come off the ground and undergo a concussion test; if found to be concussed, he is not allowed to return to the field for the remainder of the game. A player may be forced to make an interchange by the umpire under the blood rule. If an umpire sees a player bleeding, he will call time-on at the next appropriate time, stopping play until the player has left the field and been replaced. Where the league has a provision to do so, an interchange steward is provided to monitor interchanges.Policing interchanges
Headcount
The primary means for controlling interchanges in most leagues (but not in the AFL) is via a headcount, currently detailed in Law 5.5 of the game. To initiate this procedure, a teamFamous headcounts
Perhaps the most famous headcount request occurred in the SANFL in Round 15, 1975. West Torrens' champion Fred Bills, playing the last of his 313 league games (having announced his retirement earlier that week) entered the field of play before John Cassin, who was injured and lying on a stretcher, had left it. This prompted West Adelaide, trailing 11.7 (73) to 12.10 (82) in the final quarter, to request a headcount. West Torrens players ran for the boundary line, while West Adelaide players wrestled with them to keep them in bounds; in the chaos, one player, identified in the match report published in '' The Advertiser'' as Norm Dare, managed to leap the fence and hide under a supporter's coat to avoid detection from the umpire. Ultimately, the count was abandoned when it became impossible to vouch for who was on the field at the time of the request, and West Torrens went on to win by three goals. The incident was celebrated as one of the sport's 150 greatest moments in the 150th year celebrations in 2008. The debacle was covered in a popular Secret Basebr>videoInterchange infringement penalties
In Round 6, 2008, and played a controversial drawn match, in which a bungled interchange late in the game left Sydney with 19 men on the field for about a minute, during which time the Swans scored the game-tying behind. Although the AFL's laws allowed for each of the Sydney players to be fined $2500 for the error, there could be no change to the match result because North Melbourne had not called for a headcount. This highlighted the impracticality of the head-count rule in a modern professional league with its rapid use of interchanges for fatigue management. A few weeks after this incident, the AFL introduced a new rule allowing the interchange steward to inform the umpires of interchange errors: specifically, when a player enters the field before the player he is replacing has left the field, or when a player is interchanged without using the interchange gate. In each case, the penalty is a free kick in the centre of the ground or at the spot of the ball at the time, whichever is the greater penalty against the offending team. If the offending team is not in possession of the ball, the umpire shall impose an additional 50-metre penalty against them. Any score or free kicks given to the opposition when an interchange infringement has occurred are cancelled. This process is seen only at the professional AFL level; lower levels of the sport still rely on the head-count rule to police interchanges. AFL captains retain the right to call for a headcount if they believe an interchange infringement has not been detected by the interchange steward (which would most likely be after an interval), but this has not yet been exercised under the new rules.Historical interchange rules and tactics
The number of interchanges allowed has followed the following time-line under Australian National Football Council (ANFC) rules: *Prior to 1930 – there was no means for either substitution or interchange. A team played with 17 on the field (19 prior to 1899) if a player was injured. *1930 – the introduction of a single substitute *1946 – the introduction of a second substitute *1978 – the replacement of two substitutes with two interchanges Following the disbandment of the ANFC, the following timeline indicates changes to interchange rules in the AFL. Other leagues have not followed this timeline: *1994 – the introduction of a third interchange, and introduction of forced interchange under the blood rule *1998 – the introduction of a fourth interchange *2011 – the replacement of four interchanges with three interchanges and a substitute *2013 – the introduction of forced interchange for concussed players, with the provision for temporary activation of the substitute while a concussion test is conducted *2014 – the addition of an interchange cap, limiting teams to 120 interchanges per game *2016 – the return to four interchanges without a substitute, reduction of the interchange cap to 90 per game *2021 – the reduction of the interchange cap to 75 a game, and introduction of a medical substitute as a fifth bench player. Historically, the interchange bench was used sparingly, and mostly to take poor-performing or players who were injured and unable to continue out of the game. There was a marked change in this at the top level as professionalism grew in the sport between 2000 and 2010, and the interchange bench began to be used much more frequently as a means of rotating players to manage player fatigue through the game and offer rest periods for hard working players and game time for young/old players. The average number of interchanges in the AFL doubled between 2007 (56 changes per team per game) and 2010 (113 changes per team per game) as coaches sought to give frequent rests to their running players. Rule changes in the 2010s and 2020s placed restrictions on the number of interchanges, on the theory that lower fatigue levels were enabling a more defensive play style which was stifling open play and scoring, and that restricting rotations and increasing fatigue could reverse that trend.Footnotes
:1. In the AFL's own account of the incident, as published on its website as part of the 150th-anniversary celebrations, the leap over the fence was credited not to Norm Dare, but to Gerry Noonan – who, like Dare, was a former Fitzroy player in the VFL who transferred to West Torrens in 1975. Additionally, the AFL's account of the incident had one other significant factual difference to the account in ''The Advertiser'': the AFL's account indicated that the match was Fred Bills' 300th match, but the account in ''The Advertiser'' makes it unequivocally clear that it was Bills' 313th and final match.References
{{reflist Australian rules football terminology Laws of Australian rules football