I knew that Sonic the Hedgehog would be a hit film long before it came out, because I have a secret weapon: a five-year-old. My son latched on to the Sonic trailer – the updated one, not the disastrous one – the instant he saw it, and we watched it over and over (and over) for months. He made me act it out. He asked for Sonic-themed birthday presents. He loved the trailer so much that, when we went to see the film, he was palpably disappointed that it didn’t contain the cover version of Blitzkrieg Bop used in the trailer. It was obvious from seeing the trailer that Sonic would be a hit.

This got me thinking. Can I use my five-year-old (and, where possible, my two-year-old) to predict the success of a film based on its trailer? This morning during breakfast, I made them sit and watch a batch, in the hope that one of them would be the next Sonic the Hedgehog. Here are my findings.

Pixar’s film about two elf brothers who semi-successfully revive their dead father doesn’t have the immediacy of Sonic the Hedgehog, but nevertheless my kids watched the trailer transfixed. Did they want to see the film? “It looks funny, because the man turns too tiny in it,” the five-year-old said, referring to the final joke in the trailer. What else did you like? “Can we watch the Sonic trailer now?” Signs for Onward’s commercial success are not good.

Peter Rabbit 2

I was forced to watch the James Corden Peter Rabbit film on a sick day a few weeks ago, and it was actually much better than I would have guessed based on its horrible trailer. So I had high hopes for the sequel, which is out this month. Five seconds into the trailer, my two-year-old shouts: “FUNNY!” And then: “THIS IS A TRAILER!” And then, when Peter Rabbit Rabbit eats a rotten apple, he shouts: “THERE’S AN APPLE IN THE TRAILER!” Then: “TOMATOES!” The trailer got two big, sustained laughs out of my kids. When it finished, the five-year-old declared it to be, “The funniest thing I ever heard,” and the two-year-old pointed at the screen and intoned the word: “Cheeky.” Based on this, I suspect Peter Rabbit 2 will be a Paddington 2-style crossover hit.

My Spy

In which hard-boiled intelligence agent Dave Bautista mimics Kindergarten Cop by looking after a child for some reason. The trailer was met with open hostility. “It’s a bit too scary and bit too boring,” the five-year-old says 10 seconds in. One minute later, he asks of Bautista: “Why does he keep killing everything, but not his family?” That’s a good question, I reply. Why do you think? “Because he likes his family, but he’s a baddie.” The two-year-old attempts to lift the mood by telling me that I look like Bautista, but it’s too little, too late. The trailer is abandoned before it ends, and this leaves no doubt that My Spy will be a gigantic flop.

Mulan

Now to the biggest surprise of the test: Disney’s forthcoming live-action Mulan remake. We’re treated to a stately panorama shot of ancient China, and the five-year-old confirms my worst suspicions by sighing and saying: “This looks too much like a grownup film.” But then an army starts running up the side of a wall and the kids are in. “Woah,” the five-year-old shouts, setting up what will almost definitely end up being a poster quote: “This is boring but cool!” Then he asks: “Is this in China?” and perks up enormously. “This has great music!” he shouts. After it ends, he says: “Awesome, very cool.” Mulan will be an inevitable hit.

Four Kids and It

After the surprise success of Mulan’s trailer, the one for the Michael Caine and Russell Brand adaptation of Jacqueline Wilson’s novel Four Children and It didn’t stand a chance. I chose the minute-long trailer, but not even it could hold their attention. “I want breakfast,” the two-year-old yelled. I tried appealing to the five-year-old. Is it good? Would you watch it? “The monster gave the kids powers,” he replied. Do you want a monster to give you powers? “No. Can I watch Sonic now?”