Evolution is paramount in football, especially in modern times. The rulebook is in a constant state of flux, and one of the most contentious quirks introduced by lawmakers was the away goals rule.

The rule may not boast the game-changing historical significance of, say, the offside law from an on-field perspective or the Bosman ruling in regards to player power in thr transfer market, but away goals did have a major say in deciding results in UEFA’s flagship competitions while it was in use.

The rule was ditched in 2021, with UEFA since reverting to a more traditional method of deciding knockout ties should they end in a draw after two legs.

The away goals rule meant that should a two-legged affair end in a draw, the team that scored the most goals away from home over the tie would advance.

In the event of an aggregate draw, away goals would essentially count for double at the end. So, for example, Tottenham advanced into the 2019 Champions League final over Ajax, despite the tie ending 3-3 after 180 minutes. They progressed because they scored three times in Amsterdam in the second leg, after they were beaten by the Dutch side 1-0 in north London.

Bayer Leverkusen reaching the 2002 Champions League final at the expense of Manchester United is another famous example of the now defunct rule in force, after a 2-2 draw at Old Trafford and a 1-1 draw in Germany.

Only if the contest ended in a draw and both teams had scored the same number of away goals would the tie would then go to extra-time and, if needed, penalties.

The away goals rule was introduced rather innocuously ahead of the 1965/66 UEFA Cup Winners’ Cup, and first invoked during the second round of the competition with Czech side Dukla Prague and Hungary’s Budapest Honved level at 4-4 after two legs.

Budapest Honved advanced because they scored three goals in Czechoslovakia as opposed to Dukla, who scored just twice in the Hungarian capital.

The rule, which was introduced to the European Cup in 1967, was brought in to encourage teams to attack away from home during a time when Italian catenaccio fever was sweeping the continent after Helenio Herrera guided Inter to back-to-back continental triumphs.

The rule survived until 2021, when UEFA announced ahead of the 2021/22 season that away goals would no longer be in play for their club competitions. The last time it was applied in the Champions League saw Paris Saint-Germain knock Bayern Munich out at the quarter-final stage in 2020/21.

The rule had long been regarded as outdated, with many welcoming the decision. Explaining why UEFA decided to ditch away goals, President Aleksander Ceferin admitted that “a decline in home advantage” was the major reason.

UEFA has reverted to the basics. No more away goals counting for double. If a two-legged tie ends in a draw, it’s standard extra-time and penalties. That’s it.