It came so high on the list of life's improbabilities that I was compelled to ponder an equivalent.
Porcine aviation? Cousin Tony apologising for bunkering up the country? Blues winning the Premiership? Wales winning another Grand Slam?
Nah! Those are all racing certainties compared with what John Jacobs has seen and put on the record. John Jacobs has seen Ben Hogan hit a shank.
The venerable English golfer, father of the PGA Tour, oracle, mentor to the mighty, was playing a tournament some years ago and was in the group ahead of the American legend when he was very nearly struck by Hogan's 70- yard shot to the green that Jacobs had just vacated.
He described the moment thus: "He ( Hogan) hit the ball clean off the socket -- right off the pipe of his pitching club.
"It flew sharply right and, as a matter of fact, very nearly hit me. I thought to myself at the time: I bet there aren't many who have seen Hogan hit a full-blooded shank."
Not many? How's that for an understatement? This is a scoop. You could write a book about it. Actually, Jacobs has written a book about it.
Not specifically about Hogan's Shank, of course, but about Hogan and the millions of shots that he hit straight. And about quite a few other famous golfers who as near as dammit mastered the game.
Fifty Years of Golfing Wisdom (Collins Willow, £14.99) is a compression of all the knowledge that Jacobs has been spreading, via his other books, over half a century.
His wisdom has nurtured many and these words will live on to aid many more. Not me, though. I have long since given up on golf teachers, not because I do not value their wisdom or their ability to dispense it but because I consider myself to be ineducable.
I have defeated some of the best coaches in the land and I no longer say this with shame. The cruellest of the many hurtful things that have been said of my swing is that it resembles that of a Persian axeman.
My swing imitates no-one; it replicates no other action. It's personal. And in my eyes that makes it art; somewhat abstract, perhaps, but art.
So while reading this book I ignored the bits about what Jacobs might do for me and dwelt on what he did for others and what his thoughts are on the skills of proper golfers. Like Sandy Lyle.
Lyle, he writes, was a worthy successor to Harry Vardon and James Braid. Technically a bit suspect, though. Takes the club back too much around the right side. But Ian Woosnam. . .
"For me, Ian Woosnam swings the club exactly the way I think it should be swung. . . he is the perfect exemplar of the secret of long hitting."
No-one applies his skills more correctly than Woosnam. Hogan didn't. "He (Woosnam) is a better Hogan, if you like -- more fluid and more correct in that he does not have to drive it through and hit as late as Hogan did."
Hang on a bit, though. Jacobs does say a few pages later that Hogan was "the greatest ball-striker who ever picked up a golf club."
Not many of us put Ray Floyd on the pantheon but in a game for hard men, which is what golf at the highest level is, Floyd bowed his will to no-one. Next to Jack Nicklaus, in Jacobs's view, Floyd had the best temperament of any player in the last 50 years. Jacobs takes his hat off to Bernhard Langer. He does not know any sportsman who has come back so many times from such fundamentally damaging technical difficulties.
He's referring to the German's putting, of course. Three attacks of the yips - at least - and still a worldclass competitor. How could Langer, with such an affliction, win twice at Augusta on the most treacherous greens in the world?
No other golfer endured as well as Sam Snead, he of the Rolls Royce swing. He almost won the US PGA Championship in 1974 at the age of 62. Only Nicklaus and Lee Trevino denied him. "For the record," Jacobs reminds us, "Sam shot a round of 60 at the age of 71."
"Snead's secrets were a soft grip and his discipline in never trying to hit too hard. Even with his driver, he was never operating at more than about 80 per cent."
The old master writes about Nick Price, who was a winner despite his temperament, about Trevino ("a lethal competitor"), about his boyhood hero, Henry Cotton, Bobby Locke, Peter Thomson and Nick Faldo.
And he gives a hefty mention to Hale Irwin, one who never needed his counsel or that of any other teacher. For that, Irwin was "close to unique." These insights, from one who so clearly knows, add up to the real fascination of this book.