IT'S a subject that has dominated pub debates for years.
Just ask Chris Waddle. Or Gareth Southgate. Or current England skipper David Beckham. Or Town star Danny Schofield.
Now a former Huddersfield man has come to their aid.
He's written a book on how to take the perfect penalty.
Dr John Haigh, 63, who now lives in Sussex, has written How To Take A Penalty: The Hidden Mathematics of Sport.
The book, published by Robson Books Ltd, was co-written by statistician Rob Eastaway.
Dr Haigh has been a mathematics lecturer at Sussex University since 1966, after finishing his PhD at Caius College in Cambridge.
He is also a lecturer for the Royal Statistical Society and an assessor on the board which selects statisticians for the civil service.
He and Mr Eastaway decided to write the book after discovering a shared love of sport.
The book covers cricket, rugby, gymnastics, athletics, darts, football and many other sports.
He said: "We had both written books before so we decided to write this one about the different ways maths turns up in sport.
"We don't seriously expect footballers being paid £90,000 a week to read it and take tips!"
But Dr Haigh hopes the book may get people interested in maths.
He said: "What I try to do is make ordinary people realise that maths is relevant to so many things."
Dr Haigh believes pairing people's passions with maths principles will make the subject more popular.
His first book, Taking Chances, was published six years ago.
It was about relevance of probability to things such as the National Lottery, betting, and `buying' the best properties in a game of Monopoly.
Now he analyses the chances involved in taking penalties.
David Beckham becomes the subject of a simplified equation; the authors assess the probability theory, as to how many times he should try and place the ball or how often he should just belt it.
The answer? Beckham needs to mix his strategies between aiming straight and placing the ball - but to do it randomly.
Dr Haigh said he began writing only after a publisher asked him to produce a layman's guide to calculated risk.
Taking Chances has since been translated into Spanish and Chinese.
Dr Haigh has just updated the book for the British market to take account of TV quiz shows like Who Wants To Be A Millionaire?.
Dr Haigh's books encourage interest in maths - but he says interest is not enough.
He feels that the quality as well as the quantity of maths students needs to improve.
He said: "The type of maths that teachers are expected to do at school has changed. Today's 17 and 18-year-olds are less technically proficient.
"They're no longer presented with a problem and asked to work it out. That's what they have to do at university but at school they're shown all the intermediate steps.
"Today's students are no less smart than we were, it's just that they haven't had the same practice. I did three hours of maths homework every evening."
