Well, that's an almost impossible question to answer - not least because we haven't got reliable balls-faced statistics for many of the early Test matches (it didn't become the norm to record that information until the last 30-40 years). In the early days there were legendary stonewallers like England's
William Scotton, a left-hander who once carried his bat through a first-class innings and scored 9 not out. During the 1950s Trevor Bailey was a famous stumbling-block for England in Tests, once scoring 68 in 458 minutes against Australia
at Brisbane in 1958-59. Later in that same match, which must have been an excruciating one for the spectators, Australia's Jim Burke went even slower, managing 28 in 250 minutes. But, using the information we
do have, the batsman who scored at the slowest rate (among those who scored more than 1000 runs in Tests) was ...
Bob Taylor, the England wicketkeeper of the 1970s and '80s. He faced 4260 balls for his 1156 runs - a rate of 27.14 runs per 100 balls. Englishmen lie second and third as well -
Mike Brearley managed a strike rate of 29.80 runs per 100 balls, and
Chris Tavare 30.60.
Bill Woodfull, the former Australian captain, comes next with 31.12, and the New Zealander
Bruce Edgar managed 32.07. Brearley also leads the way in ODIs, although he only scored 510 runs in them off 1120 balls, a strike rate of 45.54 runs per 100 balls. Top among those who scored more than 1000 runs in ODIs is Edgar (49.23).