Slow-motion replays help referees make better decisions

Slow-motion replays used as part of the video assistant referee (VAR) system have a positive impact on decisions made on the field, new research suggests.

Eighty professional football officials from the Premier League and Championship took part in research led by the University of Lincoln. They each watched video clips of incidents from different European leagues, making decisions about how much contact was made, whether it was deliberate and what disciplinary sanction they would apply.

The research found that when played back in slow-motion compared to real-time, yellow-card offences were judged as less serious, and red-card offences as more serious. This indicates that slow-motion replays may enhance official's ability to distinguish between moderate and severe offences.

VAR was introduced to the Premier League at the start of the 2019/20 season, to help decision-making in potentially game-changing incidents, such as red-card decisions.

But some pundits have raised concerns about whether slow-motion replays give a false impression of how much time players have to react, making their actions appear more intentional.

Lead author and professor of vision science at the University of Lincoln, Dr. George Mather, said: "The referees made decisions about sixty different clips from professional football matches in European leagues, viewed either in slow-motion or at real-time speed.

"We found no evidence in our results that slow-motion can by itself bias refereeing decisions by making incidents appear more intentional. Instead, the data show that slow-motion can actually help referees to distinguish between yellow-card and red-card incidents."

The researchers suggest that rules and protocols governing the use of slow-motion replays could be relaxed in light of the research, which has been published in Royal Society Open Science.