Imagine a golfer from the EuroPro Tour - the third tier of professional golf in Europe - qualifying for the Open Championship, then holing an eagle putt at the 72nd hole to edge out World No.1 Rory McIlroy for the Claret Jug and giant cheque.
Alternatively a young lass from the Scottish girls amateur team plays out of her size 4 FootJoys to beat the world's best to claim the biggest prize in women's golf at St Andrews next year.
Both feats would be regarded as highly unlikely and surely the biggest upsets in the game since Old Tom Morris wielded a hickory cleek.
Currently that achievement is recognised my many authorities worldwide as belonging to Jack Fleck - a journeyman club pro whom, in 1955, caught the legendary Ben Hogan after four rounds of the US Open - then beat him in a playoff.
The Longest Shot, researched and written by golf blogger Neil Sagebiel, from Virginia, USA, tells how Fleck, a teaching pro at pay-and-play courses in Davenport, Iowa scraped together fees to contest the PGA Tour but with little success until he qualified for the US Open at Olympic Club, San Francisco.
He trailed the leaders by nine shots after 18 holes but gradually ground his way on to the leaderboard over the next three days. With the back nine still to play his idol Hogan had already been heralded the champion, but Fleck, who served in the US Navy during the D-Day landings in Normandy, holed a pressure putt to force an improbable playoff.
There aren't too many appropriate images in the book which is a little disappointing but the author's imaginative narrative more than makes up for it.
It also gives a fascinating insight into Hogan's character, avoiding death by inches in a 1951 car crash to become one of the game's great icons.
Jack Fleck, the oldest surviving major champion, celebrates his 90th birthday today (November 7) at his home in Arkansas - the same date as my late father who would have chalked up a century alongside Hogan (also born in 1912), had he survived.
For many reasons the book is particularly poignant.
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