Banning players won't change behaviour though when the incidents are accidents that are mostly unavoidable in a game of rugby.
This is different from stopping players tackling others in the air or flying into rucks, this is about players getting their timings/ height wrong. We are punishing accidents and that won't change anything if the player didn't want to do it in the first place and (the key is) doesn't have a reasonable time to adjust.
Exactly the same was said about tackling in the air, and yet carding players did pretty much put a stop to it, and then they were able to ease off and apply more nuance.
I disagree that most head on head collisions are unavoidable by people tackling lower thereby not putting their heads in the same smal volume of space as someone else's head.
But we've had this discussion repeatedly on more relevant threads.
Just like not being in the landing space of someone in the air, change your timing and location, and you won't have to make a split second alteration.
IMO the problem isn't the sanction, it's that the chance of getting caught and sanctioned is too low, so the percentage play is still to go high and accept the (officiating) risk.
Again, this has all been discussed as nauseum in the relevant threads.
How much of a game would you review if it wasn't seen in real time? Surely you should review the whole game for head on head contact. (not saying you should)
After the event, the citing commissioner should absolutely look at the whole of every match, it's literally their job. I would propose the idea that they also look at yellow-card head contacts as well, and just issue them retrospectively, even if not meeting the criteria for a full disciplinary panel.
Every head contact should have a HIA ie Ford for England. I don't really get why they don't tbh. My understanding is with subconcusive impacts another issue that's bubbling under the surface. You don't even necessarily have symptoms.
Agreed, and have said so elsewhere repeatedly.
As for subconcussive impacts, AFAIK there is no test for them, but it's still why we need to reduce head contacts full stop. There's only so far that it's possible to do so, but we have an obligation to go as far as it is reasonably possible.
ETA: the general discussion on head contacts, tackle heights, sanctions really isn't for this tread, and I've no interest in relitigating old specific threads in this match thread, so it's my last word here on such things.
@Rosso Verde e Nero is a new poster, and posed a fair question, which deserved a response, but not a co porte détail into old and tired arguments.