Sixty years after Sir Don Bradman ended his Test career with a batting average of 99.94, a cricket statistician claims that he has found the "missing" four runs that would take the Australian legend's average to the magical 100 mark.

"Don Bradman's Test average - 99.94 runs per dismissal - is entrenched in Australian folklore, and the story of the Don's final innings, out for a duck when just four runs would have taken his average to 100, has been told countless times.

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"Just four runs, spread over a career of almost 20 years and more than 197 hours at the crease. It is worth asking: just how sure can we be that the number is correct?" statistician Charles Davis wrote in Australian newspaper The Sydney Morning Herald.

"As it happens, my recent research has shown that it could be wrong: a tantalising clue to four missing runs has been found," he claimed.

Davis said he has found the "missing four runs" of Sir Don, who passed away in 2001, in some previously undiscovered Test statistics after extensive research.

"In the scorebook of the epic eight-day fifth Test of 1928-29 against England [Images] in Melbourne, won by Australia [Images] by five wickets, there is a "problem" boundary in the final stages, when Bradman was batting with Jack Ryder," he elaborates.

"The relevant sections of Bill Ferguson's original score are illustrated: there are four runs attributed to Ryder that are in the wrong place in both the batting section of the score and in the bowling section (Maurice Tate's 35th over). There is no doubt that a recording error of some kind has occurred. So where do these runs belong?," he asked.

"Perhaps Ryder scored them at some other point of the innings. Perhaps they were not scored at all (in which case Australia, technically, did not win the match). More importantly, perhaps they were scored by Bradman. Just perhaps," Davis says.

He reasons that score-recording is a tedious process and discrepancies cannot be ruled out and such small errors perhaps hold the key to those four runs that would make the most astonishing Test statistic of all time.

"You will not find a scorebook that says Bradman scored x when the accepted score is y. It is more subtle: a batsman's strokes may not add up to his score or, more commonly, there are mismatches between strokes attributed to batsmen and the strokes marked against bowlers," he pointed out.

"There are surviving scorebooks for many Tests of the past. All but seven of Bradman's Tests are represented, preserved in libraries at Lord's, Cricket NSW, and elsewhere."

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Davis said most of "these anomalies are inconclusive."

"There are a number of possible resolutions to the question over Ryder's four runs in that Melbourne Test of 1928-29. They are complicated by the presence of an unmarked leg bye.

"At least one resolution involves transferring the boundary to Bradman. If so, a "Holy Grail" of statisticians, four more runs to Bradman, has been found, and the "perfect" average of 100.00 achieved," he said.

Davis claims that scorebooks involving Bradman have not been scrutinised properly.

"Most of Bradman's scorebooks have not been checked at this level of detail. It is painstaking work. However, the chances of finding other anomalies, based on experience with many other scores, seem high," he said.