The advent of the Video Assistant Referee (VAR) in the Premier League hasn't gone smoothly since its introduction in 2019.
Its introduction into English football was delayed, with the Premier League being the last of the "Big Five" leagues in Europe to adopt it. The Bundesliga and Serie A were early adopters in 2017-18, but the Premier League hesitated for two years before voting to use it from the 2019-20 season.
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High-profile errors and protocol missteps have dogged Professional Game Match Officials Limited (PGMOL), the body that oversees refereeing, ultimately resulting in the Premier League being the only "Big Five" league not to have a single referee selected by FIFA to act as a VAR at the World Cup later this year.