This series is primarily concerned with a draughts-playing program which Strachey began in his spare time while teaching at Harrow School. Strachey heard of the work on the Pilot ACE machine on 22 January 1950; by 23 February 1951 he had devised a program for the machine using eight delay lines (its full capacity), and the program was tried out on 30 July 1951 at the National Physical Laboratory at Teddington. (We are indebted to Mr. M. Woodger for this detailed information.)

The program developed into an attempt at autocoding (see Strachey's letters to A.M. Turing (MS. Eng. misc. b. 258/C.22) and M. Woodger (MS. Eng. misc. b. 258/C.23) of May 1951) and was modified and tried out on the Ferranti Mark I machine at Manchester University. Its success, and Strachey's skill in programming, led to his appointment to the National Research Development Corporation in November 1951.

The original program was reconstituted by B. Munday at the National Physical Laboratory in 1958 to be run on DEUCE (the successor of the Pilot ACE), and a copy is included by the courtesy of Mr. M. Woodger as MS. Eng. misc. b. 258/C.26 below.

For the continuation of Strachey's work on the draughts-playing program on the Manchester machine, see MS. Eng. misc. b. 258/C.27-MS. Eng. misc. b. 258/C.33.