Sydney Copley: © Getty Images

It is the fate of the substitute fielder to remain forever anonymous. Whatever remarkable feats he achieves, the best he can ever hope for is a c sub in the scorecard, and any achievements do not count for the records.

Almost always, the substitute's role is unremarkable. Occasionally, he does something special. For example, when England beat West Indies at Lord's in 1995, Paul Weekes, a county journeyman at Middlesex fielding because Graham Thorpe had the flu, took two good and crucial short-leg catches. And at Trent Bridge in 1930, Sydney Copley, one of the most anonymous of all substitutes, took one of the most crucial catches of them all.

The fourth day of the first Ashes Test started with the game evenly poised. Australia, set a daunting target of 429 to win, resumed at 90 for 1, but England were handicapped by the absence of Harold Larwood, who did not take the field at the start of play as he was suffering from gastritis.

Copley, then 24, was on the groundstaff at Trent Bridge, but had not threatened to break into the first team; in fact, he had only made four undistinguished second-team appearances in 1926 and 1927. But he had a reputation as a good outfielder.

"On my arrival that morning the tannoy system was calling my name to report to the secretary's office," he recalled years later. "On arriving there I met the captain, Percy Chapman, and Jack Hobbs. I was asked how I would like to substitute for England. I was thrilled to do so, of course. I had done a lot of 12th-man duty for the Nottinghamshire XI so I was not too nervous, just a little. Hobbs soon put me at ease with a few kind words."

Although Australia soon lost Bill Ponsford and Alan Kippax, their most dangerous batsmen, Don Bradman and Stan McCabe, began to build a frustrating stand. Walter Robins eventually dismissed Bradman for 131, but McCabe was still there and beginning to cut loose when Copley's moment came.

"Right from the first ball I fielded things went well for me," he explained. "Maurice Tate had said to me how Stan was very strong on the on side and to watch out if he pitched short, as Stan would be on to it like a flash.

"I was at mid-on when it happened, being on the move already as I was always on the lookout for this shot against the short ball. Stan played it hard and low not more than six inches off the ground. I made many yards to reach it and with a terrific effort I seized the ball and turned a somersault, still clinging to the ball, to break up a dangerous partnership. I was picked off the ground by a very jubilant captain. It certainly turned out a great day for me!"

Wisden's report supports Copley's own recollection, commenting that he "made a lot of ground, took the ball at full length and although rolling over, retained possession." That ended any lingering hopes Australia had, and that afternoon England completed a 93-run victory.

Copley made his first-class debut for Nottinghamshire against Oxford University the following week, but achieved little - and that was the extent of his first-class career. He moved north to Cupar in Scotland, where he was player-coach for six years, and from there to King William's College on the Isle of Man where he was coach and head groundsman for more than 30 years.

His role in cricket history is ephemeral and almost entirely unrecorded. But for one glorious moment, he was the story.

Other famous English substitutes
1982 - Neil Taylor, the Kent batsman, held a sharp catch off Ian Botham to remove India's Sandip Patel
1984 - Don Topley of the MCC groundstaff held a steepling catch at long leg at Lord's when Malcolm Marshall hooked Bob Willis ... only to step back over the rope
1989 - Another member of the Lord's groundstaff, Robin Sims, caught Allan Border for 1 at long leg
1995 - A mixed performance from Ben Spendlove, on the Derbyshire staff, who held two catches against South Africa at Edgbaston only to drop Jonty Rhodes, a miss which went some way to enabling South Africa to avoid the follow-on

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The Cricketer Various 1974 and 1930

Martin Williamson is managing editor of Cricinfo