This weekend Sam Skinner should be lacing his boots to play for Exeter in a Premiership final. But in the last round of the regular season, he bent his 6ft 5in frame to tackle a 5ft 7in scrum‑half. He caught him in the head and thus became the latest player to be shown a red card.

Skinner misses the climax of the season because of the mandatory ban. And he can forget about any call-ups to play for the Lions or Scotland this summer, too. It is a rank injustice, at which far too many are prepared to shrug their shoulders while repeating some mantra, handed down from on high, about these red cards being for the players’ own good. There is no evidence so far to suggest this.

In the last week of the 2019 World Cup the game’s governing body, World Rugby, announced “best-ever player welfare outcomes”. The subsequent headlines around the world joined in the refrain: the campaign for a safer game was being won. And yet in the official injury audit of the World Cup, published in the South African Journal of Medical Science in February 2020, the numbers tell a different story.

The headline figure in the 2019 press release declared the number of replacements for injury in a match had fallen from 2.08 at the 2015 World Cup to 1.13 in 2019. But World Rugby has explained to us that the 2019 figure left out all injuries owing to concussion, because they were being dealt with elsewhere in the release. The figure for 2015, however, did include concussions, the game’s most common injury. This detail was omitted.

The press release also declared that concussions had fallen from 2015’s figure of 12.5 per 1,000 player hours to 10.5 in 2019, a fall of 16%. This was presented as fact before the tournament had finished, in effect declaring victory before the final whistle. In the end, World Rugby explains, two further cases came to light from preceding matches, with two more in the final, bringing the real figure up to 12.2 per 1,000 player hours, a rather less dramatic fall of 2.2%, partially explained by a 1% drop in 2019’s collision rate. No public correction was issued.

A spokesperson for World Rugby told us: “We can and should encourage a healthy, open and transparent debate about the science and the statistics at all levels of the game,” and that “it is only through honest, transparent and engaged dialogue that we can better understand the impacts on player welfare”.

World Rugby’s best work to date is a study of 611 head injury assessments (HIAs) across three seasons of elite rugby. It gave rise to the policy of sending off players for contact with the head, which has been in place since January 2017.

The data supplied is rich, but the key set is the one relating to the number of HIAs when the tackler is upright. The chances of an HIA then are 44% higher, which is why the stated aim of the red-card policy is for tacklers to bend at the waist. But of those 611 HIAs only 164 occurred when the tackler was upright. It is thus possible to calculate the very best hypothetical reduction we could expect if we were never to see another upright tackler again. The answer is 50 out of the 611, or 8%. Incidentally, the number of HIAs resulting from a high tackle was 18, or 3%.

We should never expect this red-card wild west to shift the dial more than fractionally on the concussion front. As for the wider question of neurodegenerative conditions in later life, we should not expect even that, because the issue there is constant pummelling over a long career.

The key problem for tacklers is that they are always one step behind. The proactive party is the player with the ball, across whom is drawn the line of legality, which is constantly shifting at high speeds. Four years in, the tackle height has come down. Big hits to the upper body are no longer practised or celebrated as they were. The tacklers are doing their best.

If the deterrent were working, there would be no more red cards by now, but still they keep coming. That is because these offences are not deliberate. Players are being sent off for – at worst – technical shortcomings, in almost every case for incidents they cannot avoid.

The Premiership in England is subject to the longest-running study of injuries in elite rugby. In the latest report, concussion rates were as high as ever. Another trial with a reduced tackle height among the Championship clubs in England, too small to be conclusive, saw concussion rates actually increase by 31%.

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A lower tackle height may not lead to lower counts of brain injury, but that is not to say it is undesirable, even if it should be achieved through education, coaching and law change. Which brings us back to World Rugby’s treatment of the data in 2019.

This is at heart a PR battle, and it is real. Rugby will never face a winding-up order on health-and-safety grounds, but it could wither from the ground up as parents and their children turn away. In such a context, a blow to the head in a high-profile game is just a bad look. Waving red cards is the easiest way for rugby to look as if it is doing all it can. The blame for the game’s crisis is thus shifted on to the scapegoated players, those same poor souls taking the pummelling in the first place for our entertainment.

If rugby can live with that as a necessary evil in the battle to win hearts and minds, so be it, but this purge by red card is of next to no health benefit to the players. Its only merit on that front is to give them a break from the pummelling while they serve their bans.