15,000 runs in first-class cricket over a five-year period:
Hobbs (6 Sep 1909 - 1 Sep 1914): 15421 runs, average 46.87 / 41 centuries. 125 catches.
Hendren (10 June 1925 - 6 June 1930): 16759 runs, average 65.98 / 62 centuries. 207 catches.
Sandham (19 Oct 1926 - 9 Sep 1931): 15337 runs, average 55.56 / 50 centuries. 65 catches.
Herbert Sutcliffe (9 Dec 1927 - 7 Dec 1932): 16835 runs, average 70.14 / 64 centuries. 112 catches.
Hammond (1 Sep 1934 - 29 Aug 1939): 16634 runs, average 60.70 / 59 centuries. 203 wickets. 214 catches.
Compton (25 May 1946 - 22 May 1951): 16890 runs, average 65.21 / 68 centuries. 305 wickets. 171 catches.
Hutton (17 Oct 1946 - 11 Sep 1951): 17645 runs, average 64.16 / 61 centuries. 183 catches.
Barry Richards (22 May 1968 - 18 May 1973): 15062 runs, average 58.15 / 43 centuries. 174 catches.
10,000 runs in five years, with no county cricket:
Bradman (8 Nov 1929 - 11 Sep 1934): 11754 runs, average 93.28 / 42 centuries. 47 catches.
Bobby Simpson (20 Nov 1959 - 17 Nov 1964): 11803 runs, average 65.20 / 36 centuries. 217 wickets. 184 catches.
Greg Chappell (8 Jan 1972 - 6 Jan 1977): 10280 runs, average 65.06 / 33 centuries. 104 wickets. 149 catches.