It is a maxim drummed into fresh-faced young news reporters before they are unleashed from training college and allowed out into the world to cause trouble.
Dog bites man: no story. Happens all the time. Not even slightly unusual.
Man bites dog, on the contrary, is a huge story, being something of a rarity.
Bearing this in mind we have not been suffering from any feelings of dreadful urgency in bringing you reports of Jenson Button’s welcome of Ross Brawn to Honda.
The fact that an underperforming driver thrown a potential lifeline grabs hold of this lifeline and tugs mightily strikes us as being firmly in the ‘dog bites man’ category of news.
But, sitting here and twiddling our thumbs while we wait for the verdict in the McLaren fuel appeal (5pm, GMT, and still nothing) we looked up at our own masthead and we remembered: Jenson Button. Core market and all that. Pull yourselves together, chaps, and get your finger out.
So here’s what he said during an Autosport question and answer session:
“I am very happy, you know. I think this is what the team needs. The guy has got so much experience in F1.
“One man does not turn round the whole team but I think his input, his guidance and his direction are going to make a big difference. He has done it all before and I am really looking forward to working with him.
“I have spoken to the guy and I cannot wait to meet up with him. I have not met him since he has become part of the team. I hope I will meet him soon and we run through a few things.
“I think everyone is excited about the new appointment. Ross coming to us is amazing but we also have lot of other people coming to the team. I expect them to do a great job, and Ross adds to that.”
Now, if anything other than “McLaren appeal thrown out” emerges from the dark bowels of the World Motorsport Council hearing, that’ll be ‘man bites dog’ territory.