A two-time PGA Championship winner, Diegel enjoyed considerable success throughout a stellar career that would ultimately earn him a place in the World Golf Hall of Fame.

Diegel's determination to succeed was legendary and prompted the great Gene Sarazen to state: "In all my years of golf, I have never seen anyone whose devotion to the game could match Leo's. It was his religion.

"Between courses at the table, Leo used to get up and practice swings. Every night he went to bed dreaming theory and every morning he awakened with some hot idea that was going to revolutionize the game."

One such idea was an idiosyncratic putting method that soon became known as 'Diegeling'. To the amusement of many, Diegel would crouch exaggeratedly over his tall putter and make a stroke with his elbows pointing out and his forearms held in a horizontal position.

The technique may have appeared somewhat comical, but it helped Diegel to win regularly on the PGA Tour, while his PGA Championship victories in 1928 and 1929 exemplified his match play prowess.

However, the American's unusual putting stroke let him down at the most inopportune time at St Andrews in 1933, as he missed out on a golden opportunity to contest a play-off for the Claret Jug.

Renowned as a nervous finisher, Diegel looked certain to record an aggregate total of 292 - a score that would have matched the leading mark of Denny Shute and Craig Wood - when he rolled a lengthy approach putt on the final green to within a couple of feet.

Yet he then contrived to miss what was essentially no more than simple a tap-in for par, leaving him one shot outside a play-off that took place the following day and was won by Open debutant Shute.

The tie for third was Diegel's third top-three finish in as many visits to The Open, but he never competed in the Championship again.

As a result, his last ever hole at The Open was a painful one.