I’ve just watched an under-16s rugby match. It was a grudge game against a team of dirty players renowned for gouging in the maul and stamping in the breakdowns. The last time we played them our winger lost two teeth. This match was clean enough at the start: straight line-outs, good tackles, no blood. But whenever our lot took the ball to ground, their forwards had their hands in the ruck. We tried to alert their ref, suggesting he try Specsavers, but he refused to give the penalty. They cheated and got away with it. Now if that isn’t an apt metaphor for the state of our exam systems, then I’m Toby Flood. Except that I play like a girl because I am one.

Any system using teacher assessment is inherently flawed because it relies on the illusion that we can be objective. Coursework modules rest on the spurious notion that teachers can switch off their natural bias when they mark. You’ve taught the kids for two years; you know Melanie’s mum has cancer, and Jody’s dad moved to London last month, taking her baby sister. Who wouldn’t put their hands in the ruck to set up a few dodgy passes?

In theory, this “human error” gets winkled out at standardising meetings where whole departments check each other’s grades. In my school, these sessions always follow the same format. My HoD brings the sandwiches and the rest of us skim over each other’s marks while fighting over the hoisin duck wraps. We don’t like challenging each other’s grades. It’s like telling someone they should be a size 14 when they’re happy squeezing into a 12.

But ignoring flabby marking is not as unprofessional as it sounds. English assessments are notoriously subjective. We never ask “Is this a C?”, but rather “Can I get away with a C for this?” because the former would suggest that there exists some absolute authority - like the Highway Code - that tells you unequivocally how to apply the marks. Alas, this is not the case. The reason we dither over problematic folders, demanding “Does my B look big on this?” is because the mark schemes, like the rest of the English syllabus, are open to interpretation. In fact, in English we rate ambivalence so highly that at A-level it has its own assessment objective: “AO3 - consider alternative interpretations” so it’s hardly surprising that we “generously interpret” the board’s grade descriptors.

Thankfully, we are used to ambiguous criteria. In the madness of key stage 3, where one teacher’s 6c is another’s 5b, two-thirds of our kids are tagged as “underperforming”. Our KS3 co-ordinator is unruffled: we’re only failing “in this particular data sort”, which suggests that somewhere there is an alternative spreadsheet reality where we meet targets, win prizes and I marry George Clooney.

Some schools really cheat, though. Earlier this month, a colleague who works as a moderator came across a suspicious folder. The bulk of it had been written in phonics and typed by the family pet. But a few perceptive handwritten additions lifted it into a pass. The distinctive, sloped script of the conclusion was identical to the teacher’s commentary. She alerted the exam board, but without further proof it stood by the school’s marks.

That’s not just putting your hands in the ruck. That’s taking steroids, bribing the ref, and bringing on the All Blacks as ringers.

Anne Thrope (Ms) is a secondary teacher in the North of England.