Question. What is the braking distance of your classic English centre forward, on a dry day, with a light head wind, chasing a speculative ball from midfield? I'll accept your answer to the nearest half-yard or 50cm.
OK, how about a nimble South American winger with the sun in his eyes? A cultured Scandinavian right-back nursing a slight hamstring injury? Come along, we haven't got all day. You don't know, do you?
Typical. Call yourself a football fan and yet you do not even bother to get a grip of the basic facts.
To be fair, you are not alone. Most players, pundits and coaches could not give you an answer either.
Thank goodness, then, for Sam Allardyce. The West Ham United manager, who has always been a pioneer in the appliance of sports science, is an avid collector of such data.
"It's like your Highway Code," said Allardyce, in reference to the motoring manual novice drivers must learn before gaining a UK driving licence.
"If you're travelling at 60mph, you don't just stop," he explained. Indeed not. As we all know, or have just Googled, you'll need 73 metres or 18 car lengths.
"If Andy is travelling at 15mph," he went on, arguably still overestimating Carroll's top speed, "he can't just stop dead when he's not going to make it."
Exactly. You cannot argue with science. Obviously, Allardyce has not yet had time to show us the braking distance data in full.
But I'm guessing it is very complex, taking into account a myriad of factors including weight-to-speed ratios, moisture levels and wind factor.
Plus, of course, whether or not the referee is watching.
Follow us @SprtNationalUAE