The profound impact of video technology on the World Cup can be laid bare today following the completion of the opening round of matches.

Analysis by British newspaper, The Daily Telegraph, has found that Russia 2018 has seen the most penalties per game, the highest percentage of goals scored from set-pieces and the fewest number of offsides per match of any World Cup at this stage of the competition since 1966, reports telegraph.co.uk.

There have also been fewer red cards per game after each country’s first fixture than at any World Cup for 32 years.

The polarising debate over the introduction of Video Assistant Referees to the game intensified on Tuesday following the non-award of two penalties to Harry Kane in England’s opening win over Tunisia.

FIFA confirmed that it would analyse both incidents in a mid-tournament review of VAR at Russia 2018, most likely after the end of the group stages.

Brazil were also demanding answers from the governing body on Tuesday over why two key decisions were not overturned during their opening 1-1 draw with Switzerland.

Whatever the rights and wrongs of using technology at the World Cup, there is little doubt that it was delivering on its promise to revolutionise the way elite football was played.

The nine penalties awarded in the opening round of games – three of them after an initial non-award was overturned – were on average the most of any World Cup for 52 years.

The percentage of goals from set- plays, 55.3 per cent, was also the highest over that period, arguably because VAR should pick up any grappling in the box.

The knowledge Big Brother was watching was also likely to be behind there having been only one red card in the 16 matches so far.

Keith Hackett, the former FIFA referee and Premier League referees chief, told The Daily Telegraph: ‘I’m not surprised by those statistics. Teams, players and managers have been warned very strongly about their behaviour and there is a bit of fear about VAR.

‘They will have been told there are 33 cameras a game watching your every move, and the referees have four colleagues in Moscow watching them. Subconsciously, that does have an effect, on a positive note, on discipline. As for penalties, that is the positive side of VAR and the clarity it gives.’

It was not so clear why there were so few offsides – just 2.81 per match – although assistant referees have been instructed to delay flagging for the infringement to avoid disallowing a legitimate goal that VAR can validate.

Hackett said: ‘As far as assistant referees are concerned, there is a degree of confusion. They have been told not to flag on tight offside calls and I have seen a number where I think they are offside but aren’t given. ‘They haven’t influenced games, but there is a sense of ignoring them unless it is a goal, in which case it will be checked by the VAR.

‘I am concerned a little that we have stepped the assistant referees away from what we expect them to do, and we have reduced their role dramatically.

‘I think they feel undermined by the fact they are being told a lot of what not to do, rather than what to do. That doesn’t help the process.’

There was also confusion among players, with Manchester City’s Kyle Walker – who conceded a soft penalty for England against Tunisia that VAR deemed had not been awarded in error – saying: ‘We’ve had a briefing, but what’s correct and what’s not? When do you ask for it? You don’t want to crowd the referee and say ‘VAR’, because then it is a yellow card.

‘I think you just have to let the referees get on with it and let them take the decisions. They have got a hard enough game as it is without putting any more confusion in it.’

Until now, FIFA had publicly backed all VAR interventions in the opening 11 games of the World Cup, but it refused to comment on the denial of penalties to England when Kane was twice bundled over. One possible reason for the VAR not overturning the decisions could be that, on the first of them, John Stones appeared simultaneously to push Ellyes Skhir, and, on the second, Kane seemed to have hold of Yassine Meriah’s arm as the pair tangled.