We dedicate today's editorial to comments by the BBC on the lessons picked from the video assistant refereeing system as tested at the Rusia 2017 Confederations Cup.
Here are excerpts:
The Confederations Cup is acting as a warm-up for next summer's World Cup in Russia. So what have we learned?
There have been plenty of teething issues with the video assistant referee (VAR) system, criticism of pitches, and hosts Russia do not look in great shape on the field.
But, despite pre-tournament fears, there have been no reported incidents of racism, the atmosphere around the tournament has been good - and there has been some pretty decent football, with
Germany and Chile reaching Sunday's final won 1-0 by the Germans.
Here we look at the major talking points from the tournament, and what pointers we can take for next summer's World Cup from the point of view of the BBC
To VAR or not to VAR?
Confusion. So much confusion. The video referees that so many managers, fans and pundits have called for have been trialled in Russia.
But plenty of issues have arisen. In the group stages, six "game-changing decisions" were made using VAR, with another 29 "major incidents" - according to Fifa's head referee Massimo Busacca. That's 35 in 12 games. Interestingly, though, it appeared not to be used in either semi-final.
Referees can decide whether they want help from the VAR, although other officials, including the video ones, can suggest he uses the technology. If he does, he has the choice of trusting the VAR's decision or viewing the footage himself on a screen on the side of the pitch.
However, fans cannot hear any of the conversations or see on a screen what the referee is watching - meaning several long delays while nobody on the pitch, on the sidelines, in the stands, or watching on TV, knows exactly what is happening (turn to page 7 for more details).
There was controversy in Chile's semi-final win, when Portugal defender Jose Fonte appeared to foul Francisco Silva in the box, but the referee did not award a penalty - or ask to see the incident again.
In the group game between Germany and Cameroun, the wrong player - Sebastien Siani - was booked in a case of mistaken identity. After referee Wilmar Roldan used the VAR, he upgraded Siani's yellow card to a red. But, after watching the video a second time, he saw Ernest Mabouka had actually committed the foul and sent him off instead.
While all this was happening, everyone else was in the dark. Cameroun boss Hugo Broos said afterwards: "I didn't understand it and I still don't understand it now."
How the Cameroun v Germany incident unfolded... (1) Ernest Mabouka fouls Emre Can. (2) A stunned Sebastien Siani is shown a yellow card. (3) Wilmar Roldan consults the VAR. (4) He comes back on and shows a red card to Siani, who applauds sarcastically as players surround the referee. (5) Roldan again goes to the VAR. (6) The referee comes on and this time sends off Mabouka - more than three minutes after he fouled Can
So, is there a future for video referees?
Referees' chief Busacca admits "many aspects should be improved" in the VAR system.
"Every referee team in every country that is supplying officials to the World Cup needs to be working with VAR every day," he said.
"In five days we did the VAR training for this competition. To implement more, to be at the level we need, we need time."
BBC World Service's Mani Djazmi had been at the tournament. He said: "The great fear among those sceptical about video technology was that it would remove talking points from football.
"In fact, so far, the opposite had happened; he concluded
"But the point of the Confed Cup is to try stuff out. It will be interesting to see if VAR will be missed when the English season kicks off without its beady eye."