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The Roar


Why doesn't World Rugby use GPS tracking to monitor offside?

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Roar Guru
24th September, 2019
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Sunday morning, my wife and I went on a bicycle ride around where we live. She had been travelling and busy at work so we limited the ride to around 30 miles.

She also “demanded” that we limit the speed to around a 100-120 beats per minute (heart rate) so we could talk.

She has become a rugby fanatic since we met in 2007. I took her to the fateful France versus All Blacks quarter-final in Cardiff and we went to Paris the next night to see Argentina play Scotland.

Since then, attending the Rugby World Cup has been important to her and we will be attending semis again this year. She is already bugging me about the next Lions tour.

She wanted to ask about Reece Hodge’s tackle and the offsides at rucks that, according to her eyes, weren’t been called. Basically, she wanted to know how I refereed those types of issues.

I told her that there is a big difference when you have TV cameras and TMOs compared to when you are on the field, with a possibly trained assistant referee on the side.


In addition, World Rugby has recently sent out a directive dealing with high tackles and shoulder charges that requires a mastering in decision theory. It becomes quite difficult to go through the entire process in your head when you have two sides aiming for opposite outcomes.

A complete understanding of the factors is hard and all the aspects to consider are overwhelming. But, in a large number of cases, it is clear.

Not in the Rugby World Cup.

She mumbled something about a wishy-washy answer and left it there.

Reece Hodge and Kurtley Beale celebrate a try

Reece Hodge and Kurtley Beale celebrate a try. (William West/AFP/Getty Images)

We then went to the offside laws, with which she was familiar, but then said that logistically, the referee has to make too many observations at the time of the ruck. She asked me what I did during a game.

You first look at the tackle and then the release. You look at player entry, possible sealing, attempt to pilfer, hands in the ruck – and then, somehow, you look at the offside line.

If a ruck lasts just a few seconds, you must go through many laws basically at the same time. Referees tend to stay looking at the ruck, and barely look at the offside line until the ball is leaving. Occasionally, you get the perfunctory message to the defence, but it is almost not policed.


This is because referees keep looking at the ball, even if it is clearly available to release.

During my referee training, the coach told us not to look at the ball when it is kicked – gravity will always bring it down – look at what is happening on the ground. But if we don’t look at the ruck, players will hold defenders and commit other peccadilloes.

In tennis, the ball is tracked and when players doubt a call, they can refer to the tracking mechanism. In Formula One, telemetry is available for all cars and speed is centrally controlled in the boxes area. In American football, the ten-yard line is marked on your TV sets and you can see where the first down marker lies.

In Test rugby, almost all coaches have telemetry transmitters providing player data relating to GPS positioning (speed, distance and the like) and possibly heart rate monitoring to address workload.

It should be possible to develop an algorithm that automatically determines the offside line in rucks and, maybe with some guidelines for the TMO, inform the referee of infractions and help facilitate the policing of rucks, scrums and line-outs

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If the technology proves effective, referees can spend more time focusing on aspects that are not easy to monitor technologically.

We have some of the tools already. Why not get World Rugby to develop this? Wouldn’t we all prefer to have these laws applied correctly?