When my family gets together we sometimes play a game called Scissors. It’s pretty cruel because it’s based solely on the ignorance of whoever hasn’t played it before; in other words, it’s more of a practical joke than a parlour game. In short, it involves sitting in a circle handing round a pair of scissors, with each person saying if the scissors are “crossed” or “uncrossed”. Obviously it has nothing to do with the state of the scissors: let the reader understand, but gradually the truth dawns on everyone and there is much chortling.

I was reminded of it today when England’s journalists, in their wisdom, decided that the state of Jeremy Corbyn’s top shirt button – “done” or “undone” – was a suitable subject for political reportage and punditry.

Urgh. The state of him. (Photo: Jonathan Brady/PA)

This in turn led to the usual Twitter feedback loop, with Corbynistas (Corbynites?) deriding the vacuity of the press. The same could be said for Corbyn’s refusal to sing the national anthem, which according to Conservative MPs apparently marked him out – along with his scruffy appearance – as the sort of dangerous madman who would probably sell us out immediately to the Bolsheviks if he had the chance.

But it does matter. And I’ll tell you for why.

Corbyn could have decided not to attend today’s Battle of Britain memorial service at St Paul’s. There’s another one in Westminster Abbey on Sunday, after all. But he did.

He could have decided not to wear a suit, or, as his general wont, he could have gone open-necked. But he didn’t.

Implication: he grasps the importance of ceremony in British society and, especially, British politics. He was attempting, in some way, to reflect this in his mode of attire and in being present in general.

I have no doubt that he was also being sincere in his attendance and in paying his respects.

The problem is that UK politics is currently dominated by a narrative of competence. I’ve talked about this before in extremely negative terms. The Tories are past masters at defining what competence is (even if it turns out not to be competence as anyone else would understand it), and then putting themselves on the right side of that line.

If Corbyn is going to try to play that game, he needs to get much better at it. His undone top button may not seem like much, but every time he does something like that, it undermines him. He is going to get a lot of harsh treatment in the media as it is – he already does – so he needs to do everything possible to avoid self-inflicted injuries.

Either you spin properly or not at all. Either you play by the rules set out by your opponents or you completely flout them. Acknowledging the rules, and then failing to stick to them, is the worst of all worlds.

Based on his performance so far, maybe the better course is for Corbyn to recognise that, as in WarGames – which I like to imagine is one of his favourite films – the only winning move is not to play.